Steganography - Knowledge

470: 813:. The simplest method to detect modified files, however, is to compare them to known originals. For example, to detect information being moved through the graphics on a website, an analyst can maintain known clean copies of the materials and then compare them against the current contents of the site. The differences, if the carrier is the same, comprise the payload. In general, using extremely high compression rates makes steganography difficult but not impossible. Compression errors provide a hiding place for data, but high compression reduces the amount of data available to hold the payload, raising the encoding density, which facilitates easier detection (in extreme cases, even by casual observation). 826:

an image the least significant bits of many images are actually not random. The camera sensor, especially lower-end sensors are not the best quality and can introduce some random bits. This can also be affected by the file compression done on the image. Secret messages can be introduced into the least significant bits in an image and then hidden. A steganography tool can be used to camouflage the secret message in the least significant bits but it can introduce a random area that is too perfect. This area of perfect randomization stands out and can be detected by comparing the least significant bits to the next-to-least significant bits on an image that hasn't been compressed.

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that were present. The size of the message that is being hidden is a factor in how difficult it is to detect. The overall size of the cover object also plays a factor as well. If the cover object is small and the message is large, this can distort the statistics and make it easier to detect. A larger cover object with a small message decreases the statistics and gives it a better chance of going unnoticed.

3106: 33: 834:. The term Stegware was first introduced in 2017 to describe any malicious operation involving steganography as a vehicle to conceal an attack. Detection of steganography is challenging, and because of that, not an adequate defence. Therefore, the only way of defeating the threat is to transform data in a way that destroys any hidden messages, a process called 455: 991:). In such a case, the technique of hiding the message (here, the watermark) must be robust to prevent tampering. However, digital watermarking sometimes requires a brittle watermark, which can be modified easily, to check whether the image has been tampered with. That is the key difference between steganography and digital watermarking. 456: 554:(IoT). Some techniques of CPS/IoT steganography overlap with network steganography, i.e. hiding data in communication protocols used in CPS/the IoT. However, specific techniques hide data in CPS components. For instance, data can be stored in unused registers of IoT/CPS components and in the states of IoT/CPS actuators. 665:

Moreover, it is feasible to utilize the relation between two or more different network protocols to enable secret communication. These applications fall under the term inter-protocol steganography. Alternatively, multiple network protocols can be used simultaneously to transfer hidden information and

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In 2015, a taxonomy of 109 network hiding methods was presented by Steffen Wendzel, Sebastian Zander et al. that summarized core concepts used in network steganography research. The taxonomy was developed further in recent years by several publications and authors and adjusted to new domains, such as

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Steganalysis that targets a particular algorithm has much better success as it is able to key in on the anomalies that are left behind. This is because the analysis can perform a targeted search to discover known tendencies since it is aware of the behaviors that it commonly exhibits. When analyzing

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are visual or aural attacks, structural attacks, and statistical attacks. These approaches attempt to detect the steganographic algorithms that were used. These algorithms range from unsophisticated to very sophisticated, with early algorithms being much easier to detect due to statistical anomalies

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The ciphertext produced by most digital steganography methods, however, is not printable. Traditional digital methods rely on perturbing noise in the channel file to hide the message, and as such, the channel file must be transmitted to the recipient with no additional noise from the transmission.

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messages, no matter how unbreakable they are, arouse interest and may in themselves be incriminating in countries in which encryption is illegal. Whereas cryptography is the practice of protecting the contents of a message alone, steganography is concerned with concealing both the fact that a secret

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Generally, though, there are many techniques known to be able to hide messages in data using steganographic techniques. None are, by definition, obvious when users employ standard applications, but some can be detected by specialist tools. Others, however, are resistant to detection—or rather it is

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All information hiding techniques that may be used to exchange steganograms in telecommunication networks can be classified under the general term of network steganography. This nomenclature was originally introduced by Krzysztof Szczypiorski in 2003. Contrary to typical steganographic methods that

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In communities with social or government taboos or censorship, people use cultural steganography—hiding messages in idiom, pop culture references, and other messages they share publicly and assume are monitored. This relies on social context to make the underlying messages visible only to certain

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Stated somewhat more formally, the objective for making steganographic encoding difficult to detect is to ensure that the changes to the carrier (the original signal) because of the injection of the payload (the signal to covertly embed) are visually (and ideally, statistically) negligible. The

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In 2008, Yongfeng Huang and Shanyu Tang presented a novel approach to information hiding in low bit-rate VoIP speech stream, and their published work on steganography is the first-ever effort to improve the codebook partition by using Graph theory along with Quantization Index Modulation in low

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On 23 April 2019 the U.S. Department of Justice unsealed an indictment charging Xiaoqing Zheng, a Chinese businessman and former Principal Engineer at General Electric, with 14 counts of conspiring to steal intellectual property and trade secrets from General Electric. Zheng had allegedly used

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In 1977, Kent concisely described the potential for covert channel signaling in general network communication protocols, even if the traffic is encrypted (in a footnote) in "Encryption-Based Protection for Interactive User/Computer Communication," Proceedings of the Fifth Data Communications

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Steganography includes the concealment of information within computer files. In digital steganography, electronic communications may include steganographic coding inside of a transport layer, such as a document file, image file, program, or protocol. Media files are ideal for steganographic

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Discussions of steganography generally use terminology analogous to and consistent with conventional radio and communications technology. However, some terms appear specifically in software and are easily confused. These are the most relevant ones to digital steganographic systems:

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Since the dawn of computers, techniques have been developed to embed messages in digital cover mediums. The message to conceal is often encrypted, then used to overwrite part of a much larger block of encrypted data or a block of random data (an unbreakable cipher like the

258:, by shaving the head of his most trusted servant, "marking" the message onto his scalp, then sending him on his way once his hair had regrown, with the instruction, "When thou art come to Miletus, bid Aristagoras shave thy head, and look thereon." Additionally, 3231:. How-to articles on the subject of network steganography (Wireless LANs, VoIP – Steganophony, TCP/IP protocols and mechanisms, Steganographic Router, Inter-protocol steganography). By Krzysztof Szczypiorski and Wojciech Mazurczyk from Network Security Group. 609:

Although not classic steganography, some types of modern color laser printers integrate the model, serial number, and timestamps on each printout for traceability reasons using a dot-matrix code made of small, yellow dots not recognizable to the naked eye — see

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not possible to reliably distinguish data containing a hidden message from data containing just noise—even when the most sophisticated analysis is performed. Steganography is being used to conceal and deliver more effective cyber attacks, referred to as

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Hildebrandt, Mario; Altschaffel, Robert; Lamshöft, Kevin; Lange, Matthias; Szemkus, Martin; Neubert, Tom; Vielhauer, Claus; Ding, Yongjian; Dittmann, Jana (2020). "Threat Analysis of Steganographic and Covert Communication in Nuclear I&C Systems".

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In 1987, Girling first studied covert channels on a local area network (LAN), identified and realised three obvious covert channels (two storage channels and one timing channel), and his research paper entitled “Covert channels in LAN’s” published in

117:) is the practice of representing information within another message or physical object, in such a manner that the presence of the concealed information would not be evident to an unsuspecting person's examination. In computing/electronic contexts, a 816:

There are a variety of basic tests that can be done to identify whether or not a secret message exists. This process is not concerned with the extraction of the message, which is a different process and a separate step. The most basic approaches of

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Dittmann, Jana; Hesse, Danny; Hillert, Reyk (21 March 2005). Delp Iii, Edward J; Wong, Ping W (eds.). "Steganography and steganalysis in voice-over IP scenarios: operational aspects and first experiences with a new steganalysis tool set".

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conversations, e.g. the employment of delayed or corrupted packets that would normally be ignored by the receiver (this method is called LACK – Lost Audio Packets Steganography), or, alternatively, hiding information in unused header

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use digital media (images, audio and video files) to hide data, network steganography uses communication protocols' control elements and their intrinsic functionality. As a result, such methods can be harder to detect and eliminate.

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There is the possibility of cataloging these algorithms based on the information held by the stegoanalyst in terms of clear and encrypted messages. It is a technique similar to cryptography, however, they have several differences:

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and steganography, disguised as a book on magic. Generally, the hidden messages appear to be (or to be part of) something else: images, articles, shopping lists, or some other cover text. For example, the hidden message may be in

790:) were used to manufacture postcards and stationery provided to German prisoners of war in the US and Canada. If POWs tried to write a hidden message, the special paper rendered it visible. The US granted at least two 666:

so-called control protocols can be embedded into steganographic communications to extend their capabilities, e.g. to allow dynamic overlay routing or the switching of utilized hiding methods and network protocols.

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In 2011 and 2012, Yongfeng Huang and Shanyu Tang devised new steganographic algorithms that use codec parameters as cover object to realise real-time covert VoIP steganography. Their findings were published in

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Passive steganalysis: does not alter the target stego, therefore, it examines the target stego in order to establish whether it carries hidden information and recovers the hidden message, the key used or

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steganography to exfiltrate 20,000 documents from General Electric to Tianyi Aviation Technology Co. in Nanjing, China, a company the FBI accused him of starting with backing from the Chinese government.

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can be used more or less undetectably for something else other than color information. If that is repeated for the green and the red elements of each pixel as well, it is possible to encode one letter of

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Printing introduces much noise in the ciphertext, generally rendering the message unrecoverable. There are techniques that address this limitation, one notable example being ASCII Art Steganography.

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WLAN Steganography – transmission of steganograms in Wireless Local Area Networks. A practical example of WLAN Steganography is the HICCUPS system (Hidden Communication System for Corrupted Networks)

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Although steganography and digital watermarking seem similar, they are not. In steganography, the hidden message should remain intact until it reaches its destination. Steganography can be used for

896:. The blue alone has 2 different levels of blue intensity. The difference between 11111111 and 11111110 in the value for blue intensity is likely to be undetectable by the human eye. Therefore, the 1007:

uses customized steganography software for embedding encrypted text messages inside image files for certain communications with "illegal agents" (agents without diplomatic cover) stationed abroad.

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There are distributed steganography methods, including methodologies that distribute the payload through multiple carrier files in diverse locations to make detection more difficult. For example,

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Ghosal, Sudipta Kr; Mukhopadhyay, Souradeep; Hossain, Sabbir; Sarkar, Ram (2020). "Application of Lah transform for security and privacy of data through information hiding in telecommunication".

1077:(CDR) software, and it involves reprocessing the entire file or removing parts from it. Actually detecting stegomalware in a file can be difficult and may involve testing the file behaviour in 405: 3128: 385: 586:, or other characteristics of a cover text can be manipulated to carry the hidden message. Only a recipient who knows the technique used can recover the message and then decrypt it. 1779: 800:, "Water-Detecting paper and Water-Detecting Coating Composition Therefor," patented 18 July 1950, and an earlier one, "Moisture-Sensitive Paper and the Manufacture Thereof," 189:

The advantage of steganography over cryptography alone is that the intended secret message does not attract attention to itself as an object of scrutiny. Plainly visible

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M. Wolf, “Covert channels in LAN protocols,” in Proceedings of the Workshop on Local Area Network Security (LANSEC’89) (T.A. Berson and T. Beth, eds.), pp. 91–102, 1989.

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In 1997, Rowland used the IP identification field, the TCP initial sequence number and acknowledge sequence number fields in TCP/IP headers to build covert channels.

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brand color laser printers. The printers add tiny yellow dots to each page. The barely-visible dots contain encoded printer serial numbers and date and time stamps.

806:, patented 20 July 1948. A similar strategy issues prisoners with writing paper ruled with a water-soluble ink that runs in contact with water-based invisible ink. 4547: 1511: 877:) relative to the hidden message, the easier it is to hide the hidden message (as an analogy, the larger the "haystack", the easier it is to hide a "needle"). So 4098: 3625: 3455: 3191:

Papers and information about steganography and steganalysis research from 1995 to the present. Includes Steganography Software Wiki list. Dr. Neil F. Johnson.

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Mazurczyk, Wojciech; Wendzel, Steffen; Cabaj, Krzysztof (27 August 2018). "Towards Deriving Insights into Data Hiding Methods Using Pattern-based Approach".

1829: 712:, which typically means the type of input, such as a JPEG image. The resulting signal, stream, or data file with the encoded payload is sometimes called the 3211: 1616: 4344: 1104:

Stegoanalytical algorithms can be cataloged in different ways, highlighting: according to the available information and according to the purpose sought.

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to correspond to a letter in the alphabet. The change is so subtle that someone who is not specifically looking for it is unlikely to notice the change.

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The principal purpose of steganography is to transfer information unnoticed, however, it is possible for an attacker to have two different pretensions:

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Since the era of evolving network applications, steganography research has shifted from image steganography to steganography in streaming media such as

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incorporate steganography with cryptography and other solving techniques since 2012. Puzzles involving steganography have also been featured in other

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It is possible to steganographically hide computer malware into digital images, videos, audio and various other files in order to evade detection by

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In 1989, Wolf implemented covert channels in LAN protocols, e.g. using the reserved fields, pad fields, and undefined fields in the TCP/IP protocol.

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Wendzel, Steffen; Mazurczyk, Wojciech; Haas, Georg. "Don't You Touch My Nuts: Information Hiding In Cyber Physical Systems Using Smart Buildings".

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Typical network steganography methods involve modification of the properties of a single network protocol. Such modification can be applied to the

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transmission because of their large size. For example, a sender might start with an innocuous image file and adjust the color of every hundredth

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Cheddad, Abbas; Condell, Joan; Curran, Kevin; Mc Kevitt, Paul (2010). "Digital image steganography: Survey and analysis of current methods".

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In 2003, Giannoula et al. developed a data hiding technique leading to compressed forms of source video signals on a frame-by-frame basis.

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Detecting physical steganography requires a careful physical examination, including the use of magnification, developer chemicals, and

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Bartosz Jankowski; Wojciech Mazurczyk & Krzysztof Szczypiorski (11 May 2010). "Information Hiding Using Improper Frame Padding".

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of the carrier. All media can be a carrier, but media with a large amount of redundant or compressible information is better suited.

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Known stego attack: the stegoanalyst knows the initial carrier target and the final target stego, in addition to the algorithm used.

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Image of a tree with a steganographically hidden image. The hidden image is revealed by removing all but the two least significant

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in which a message (being simply an identifier) is hidden in an image so that its source can be tracked or verified (for example,

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Active steganalysis: changes the initial stego target, therefore, it seeks to suppress the transfer of information, if it exists.

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Stegomalware can be removed from certain files without knowing whether they contain stegomalware or not. This is done through

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Examples of this include changing pixels in image or sound files, properties of digital text such as spacing and font choice,

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Stegomalware: A Systematic Survey of Malware Hiding and Detection in Images, Machine Learning Models and Research Challenges

976:) always introduce some error to the decompressed data, and it is possible to exploit that for steganographic use, as well. 647:

In 2005, Steven J. Murdoch and Stephen Lewis contributed a chapter entitled "Embedding Covert Channels into TCP/IP" in the "

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before applying its beeswax surface. Wax tablets were in common use then as reusable writing surfaces, sometimes used for

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Wendzel, Steffen; Keller, Joerg (20 October 2011). "Low-Attention Forwarding for Mobile Network Covert Channels".

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Chosen stego attack: the stegoanalyst perceives the final target stego and the steganographic algorithm used.

2683:"Secret Code in Color Printers Lets Government Track You; Tiny Dots Show Where and When You Made Your Print" 2542:

Mazurczyk, Wojciech; Wendzel, Steffen; Zander, Sebastian; Houmansadr, Amir; Szczypiorski, Krzysztof (2016).

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Mileva, Aleksandra; Velinov, Aleksandar; Hartmann, Laura; Wendzel, Steffen; Mazurczyk, Wojciech (May 2021).

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Kamran Ahsan, “Covert Channel Analysis and Data Hiding in TCP/IP,” MSc Thesis, University of Toronto, 2002.

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Known message attack: the stegoanalyst owns the stego target and the hidden message, which is known to him.

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had Morris S. Kantrowitz describe in general terms the development of this paper. Three prototype papers (

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Misspelling names or words that are popular in the media in a given week, to suggest an alternate meaning.

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Placing the message in a physical item has been widely used for centuries. Some notable examples include

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2011 Seventh International Conference on Intelligent Information Hiding and Multimedia Signal Processing

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Chosen message attack: the stegoanalyst, following a message selected by him, originates a stego target.

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Known cover attack: the stegoanalyst comprises the initial conductive target and the final target stego.

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between the visible lines of a private letter. Some implementations of steganography that lack a formal

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In Proc. of: The Tenth International Multi-Conference on Advanced Computer Systems ACS'2003, pp. 31–40

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B. Xiao, Y. Huang, and S. Tang, "An Approach to Information Hiding in Low Bit-Rate Speech Stream", in

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sent a warning about a forthcoming attack to Greece by writing it directly on the wooden backing of a

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In 2005, Dittmann et al. studied steganography and watermarking of multimedia contents such as VoIP.

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Numerous techniques throughout history have been developed to embed a message within another medium.

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Proc. SPIE, Electronic Imaging, Security, Steganography, and Watermarking of Multimedia Contents VI

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Wojciech Mazurczyk & Krzysztof Szczypiorski (November 2008). "Steganography of VoIP Streams".

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An overview of digital steganography, particularly within images, for the computationally curious

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Proceedings 2015 IEEE International Conference on Pervasive Computing and Communications (PerCom)

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and on other digital communication media. It is not clear how common this practice actually is.

121:, message, image, or video is concealed within another file, message, image, or video. The word 4834: 4512: 4450: 4430: 4379: 4136: 3388: 3331: 3239: 1425: 1042: 835: 421: 4399: 4065: 3648: 3494: 3440: 3218: – 1996 paper by Craig Rowland detailing the hiding of data in TCP/IP packets. 2700: 2403: 2241:"Steganography in TCP/IP Networks. State of the Art and a Proposal of a New System – HICCUPS" 957: 925: 897: 852: 611: 547: 36:

The same image viewed by white, blue, green, and red lights reveals different hidden numbers.

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Disappearing cryptography 3rd Edition: information hiding: steganography & watermarking

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Wendzel, Steffen; Zander, Sebastian; Fechner, Bernhard; Herdin, Christian (16 April 2015).

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Proceedings of the 13th International Conference on Availability, Reliability and Security

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Network steganography covers a broad spectrum of techniques, which include, among others:

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Social Steganography: how teens smuggle meaning past the authority figures in their lives

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Fridrich, Jessica; M. Goljan; D. Soukal (2004). Delp Iii, Edward J; Wong, Ping W (eds.).

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Information Hiding in Communication Networks: Fundamentals, Mechanisms, and Applications

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uses 8 bits to represent each of the three color values (red, green, and blue) of each

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Auctor Sapientissimus Conseruans Angelica Deferat Nobis Charitas Potentissimi Creatoris

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In 2002, Kamran Ahsan made an excellent summary of research on network steganography.

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Digital steganography output may be in the form of printed documents. A message, the

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Murdoch, Steven J.; Lewis, Stephen (2005), "Embedding Covert Channels into TCP/IP",

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3. Finally, the audio is analysed through a spectrogram, revealing the initial image

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Tuptuk, Nilufer; Hailes, Stephen. "Covert channel attacks in pervasive computing".

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Giannoula, A.; Hatzinakos, D. (2003). "Compressive data hiding for video signals".

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is the signal, stream, or data file that hides the payload, which differs from the

662:(PDU), to the time relations between the exchanged PDUs, or both (hybrid methods). 46: 2899: 2827: 2055:

International Conference on Nuclear Security: Sustaining and Strengthening Efforts

1944: 1699: 601: 4730: 4292: 4221: 4043: 4018: 3952: 3914: 3851: 3228: 3215: 3205:(San Diego, CA, 6–8 February 2002). NDSS 2002. Internet Society, Washington, D.C. 2777: 2511: 1674:

Proceedings 2003 International Conference on Image Processing (Cat. No.03CH37429)

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In a set of files, the files that are considered likely to contain a payload are

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Information hiding: steganography and watermarking: attacks and countermeasures

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Disappearing cryptography: information hiding: steganography & watermarking

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Disappearing Cryptography: Information Hiding: Steganography & Watermarking

2086: 2069: 1198: 1192: 1078: 425: 224: 161: 126: 3194: 3168: 2070:"Comprehensive analysis of MQTT 5.0 susceptibility to network covert channels" 1964:"Pattern-Based Survey and Categorization of Network Covert Channel Techniques" 1848: 1798: 1681: 1021: 802: 796: 4828: 4808: 4287: 4272: 4001: 3969: 3846: 3765: 3585: 3544: 3524: 3415: 3373: 3348: 2880:

Chaganti, Raj; R, Vinayakumar; Alazab, Mamoun; Pham, Tuan (12 October 2021).

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identified through some type of statistical analysis can be referred to as a

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Hiding a picture that can be traced by using Paint or any other drawing tool.

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Stego only attack: the stegoanalyst perceives exclusively the stego target.

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Academic work since 2012 demonstrated the feasibility of steganography for

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generates ciphertexts that look perfectly random without the private key).

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Józef Lubacz; Wojciech Mazurczyk; Krzysztof Szczypiorski (February 2010).

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is modified in some way so as to contain the ciphertext, resulting in the

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The first recorded uses of steganography can be traced back to 440 BC in

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Information Hiding Techniques for Steganography and Digital Watermarking

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Liao, Xin; Wen, Qiao-yan; Shi, Sha (2011). "Distributed Steganography".

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Huang, Yongfeng; Liu, Chenghao; Tang, Shanyu; Bai, Sen (December 2012).

1635: 4803: 4798: 4725: 4720: 4684: 4679: 4674: 4669: 4277: 4033: 4013: 4006: 3986: 3893: 3519: 3489: 3484: 3445: 2506:. Lecture Notes in Computer Science. Vol. 7025. pp. 122–133. 1387: 1332:. Security, Steganography, and Watermarking of Multimedia Contents VI. 965: 570: 333: 263: 1735: 1349: 881:, which contain much data, are sometimes used to hide messages on the 4756: 4258: 4253: 4191: 4028: 3841: 3770: 3694: 3509: 1891: 1439: 1246: 949: 809:

In computing, steganographically encoded package detection is called

564: 369:

Hiding a message in the title and context of a shared video or image.

267: 259: 251: 241: 190: 3221: 3203:

Proceedings of the Network and Distributed System Security Symposium

3188: 1989: 1716:

Security, Steganography, and Watermarking of Multimedia Contents VII

4262: 3876: 3554: 3514: 3261: 3135:

external links, and converting useful links where appropriate into

3074: 2890: 2051: 1383: 1166: 1052:

incorporate steganography and other solving techniques since 1981.

882: 583: 341: 4558: 2485: 2438: 2270:"Steganography 2.0: Digital Resistance against Repressive Regimes" 1980: 1512:"How a Saxophonist Tricked the KGB by Encrypting Secrets in Music" 4776: 3962: 2642:"What's Hidden in That Picture Online? Seeing Through "Stegware"" 3017: 2541: 1260: – Software for embedding hidden data inside a carrier file 32: 3430: 3254:

2006 paper by Konakhovich G. F., Puzyrenko A. Yu. published in

3178: 2984: 2645: 1877: 889: 791: 237: 3252:

Computer steganography. Theory and practice with Mathcad (Rus)

2324: 182:, while key-dependent steganographic schemes try to adhere to 4705: 3234: 3189:

Information Hiding: Steganography & Digital Watermarking.

2597:"HICCUPS: Hidden Communication System for Corrupted Networks" 1915:

Proceedings of the 2017 IEEE Security & Privacy Workshops

1579: 1207: – Practice and study of secure communication techniques 941: 906: 902: 893: 862: 763: 203: 3663: 2916:"Finding a Content Disarm & Reconstruction (CDR) Vendor" 2067: 1830:"Steganography Integration Into a Low-Bit Rate Speech Codec" 1408: 873:

The larger the cover message (in binary data, the number of

541: 2736: 2109:

Girling, C.G. (February 1987). "Covert Channels in LAN's".

1380:"Confounding Carnivore: How to Protect Your Online Privacy" 973: 857:

Some modern computer printers use steganography, including

568:, may be first encrypted by traditional means, producing a 337: 88: 82: 64: 58: 1961: 1320: 73: 2718:"GE Engineer Charged in Elaborate Theft of Trade Secrets" 1266: – Electronic identifier embedded in an audio signal 1107: 874: 762:, prisoner of war camps gave prisoners specially-treated 389: 76: 61: 2353: 1880:

Transactions on Emerging Telecommunications Technologies

1778:

Huang, Yong Feng; Tang, Shanyu; Yuan, Jian (June 2011).

728:

and is typically expressed as a number between 0 and 1.

447:

1. The word "Knowledge" is drawn using computer software

4548:

Counterintelligence and counter-terrorism organizations

3073:

Petitcolas, Fabien A.P.; Katzenbeisser, Stefan (2016).

3033:

Petitcolas, Fabien A.P.; Katzenbeisser, Stefan (2000).

1837:

IEEE Transactions on Information Forensics and Security

1787:

IEEE Transactions on Information Forensics and Security

994: 536:

IEEE Transactions on Information Forensics and Security

287:" that can hide information in a Latin praise of God. " 3456:

Cryptographically secure pseudorandom number generator

2594: 2267: 2238: 3054:

Johnson, Neil; Duric, Zoran; Jajodia, Sushil (2001).

2393:"Practical Internet Steganography: Data Hiding in IP" 2010: 1614: 1195: – Method of indirect notification of a subpoena 106: 85: 70: 52: 49: 3267: 2430:

On the Move to Meaningful Internet Systems: OTM 2008

1712: 1615:

Bender, W.; Gruhl, D.; Morimoto, N.; Lu, A. (1996).

1177:

Pages displaying wikidata descriptions as a fallback

952:

equipment. In general, electronics that digitize an

79: 55: 2879: 1671: 1551:, Boing Boing, 22 May 2013. Retrieved 7 June 2014. 511: 494:encoded as sound in the song "My Violent Heart" by 408:

Image of a cat extracted from the tree image above.

67: 25:. For the prefix "Stego-" as used in taxonomy, see 1136: 155:The first recorded use of the term was in 1499 by 3264:a Free and Open Source steganography web service. 3195:Detecting Steganographic Content on the Internet. 3119:may not follow Knowledge's policies or guidelines 2778:"Cicada 3301: The darknet treasure trail reopens" 2630:, Morgan Kaufmann Publishers, Amsterdam; Boston 2390: 2354:Kamran Ahsan & Deepa Kundur (December 2002). 4826: 2875: 2873: 2211:, Springer Berlin Heidelberg, pp. 247–261, 1912: 746: 1827: 1189: – Method for exposing an information leak 1175: – computer message obfuscation technology 1163: – Method for hiding data on a floppy disk 987:) or even just to identify an image (as in the 948:, it may be noise from recording techniques or 868: 3184:Examples showing images hidden in other images 2941:"Content Disarm and Reconstruct – SecureIQLab" 2775: 2325:Steven J. Murdoch & Stephen Lewis (2005). 2159:"Covert channels in the TCP/IP protocol suite" 1409:Petitcolas, FAP; Anderson RJ; Kuhn MG (1999). 1169: – Text formed from parts of another text 794:related to the technology, one to Kantrowitz, 673:Steganophony – the concealment of messages in 4574: 4092: 3679: 3287: 3171:by Chris League, Long Island University, 2015 2999: 2966: 2870: 2622: 2620: 2571:"Vice Over IP: The VoIP Steganography Threat" 2499: 2293: 1777: 1099: 21:For the process of writing in shorthand, see 3006:. Amsterdam: MK/Morgan Kaufmann Publishers. 2973:. Amsterdam: MK/Morgan Kaufmann Publishers. 2206: 1219: – Marker covertly embedded in a signal 1014: 463:2. The image is converted into an audio file 4106: 3246:File Format Extension Through Steganography 2400:Texas Wksp. Security of Information Systems 956:suffer from several noise sources, such as 4581: 4567: 4099: 4085: 3686: 3672: 3294: 3280: 2730: 2617: 2535: 2239:Krzysztof Szczypiorski (4 November 2003). 770:. An article in the 24 June 1948 issue of 291:" for example contains the concealed word 3155:Learn how and when to remove this message 2889: 2484: 2437: 2174: 2111:IEEE Transactions on Software Engineering 2085: 1979: 1429: 1249: – Study of signs and sign processes 1231:– Hiding a message using musical notation 846: 685: 633:IEEE Transactions on Software Engineering 582:. For example, the letter size, spacing, 542:Cyber-physical systems/Internet of Things 2639: 1927: 1676:. Vol. 1. IEEE. pp. I–529–32. 776:United States Government Printing Office 600: 403: 383: 308: 213: 31: 4513:Scientific & Technical intelligence 2658: 2595:Krzysztof Szczypiorski (October 2003). 2391:Kundur D. & Ahsan K. (April 2003). 2327:"Embedding Covert Channels into TCP/IP" 2248:Institute of Telecommunications Seminar 2156: 2108: 1942: 1314: 913:changes are indistinguishable from the 704:is the data covertly communicated. The 359: 142:), meaning "covered or concealed", and 27:List of commonly used taxonomic affixes 4827: 3936:Chinese espionage in the United States 3222:Network Steganography Centre Tutorials 2913: 2706:. United States Department of Justice. 2503:Communications and Multimedia Security 2268:Patrick Philippe Meier (5 June 2009). 1949:Pictureworthsthousandwords.appspot.com 1480: 1478: 1377: 1108:According to the information available 4562: 4080: 3667: 3275: 2296:"Covert Channels in the TCP/IP Suite" 635:, vol. SE-13 of 2, in February 1987. 4335:By alliances, nations and industries 3931:Chinese intelligence activity abroad 3248:by Blake W. Ford and Khosrow Kaikhah 3099: 2640:Lancioni, German (16 October 2017). 1005:Russian foreign intelligence service 995:Alleged use by intelligence services 4588: 3997:Interpersonal (HUMINT) intelligence 3209:Covert Channels in the TCP/IP Suite 1475: 1055: 1032: 924:point of view, that means that the 379: 13: 1509: 1037:The puzzles that are presented by 1025:by cryptographer William Easttom ( 400:. The hidden image is shown below. 14: 4851: 3832:Computer and network surveillance 3240:Steganography by Michael T. Raggo 3235:Invitation to BPCS-Steganography. 3095: 2776:Jane Wakefield (9 January 2014). 2356:"Practical Data Hiding in TCP/IP" 1075:content disarm and reconstruction 940:. For a digital image, it may be 774:by the Technical Director of the 16:Hiding messages in other messages 3867:Short-range agent communications 3644: 3643: 3301: 3201:and Peter Honeyman published in 3104: 2661:Defenders Guide to Steganography 2157:Rowland, Craig H. (5 May 1997). 1463:(in German). Digitale Sammlungen 1201: – Computer security attack 605:Yellow dots from a laser printer 512:Steganography in streaming media 480: 468: 452: 440: 305:List of steganography techniques 45: 4483:Words of estimative probability 4345:Operational platforms by nation 2933: 2907: 2845: 2820: 2795: 2769: 2724: 2710: 2693: 2675: 2652: 2633: 2588: 2562: 2493: 2472: 2421: 2384: 2347: 2318: 2287: 2261: 2232: 2200: 2191: 2150: 2141: 2102: 2061: 2045: 2004: 1955: 1936: 1921: 1906: 1871: 1821: 1771: 1750: 1706: 1665: 1608: 1573: 1378:Pahati, OJ (29 November 2001). 1137:According to the purpose sought 1088: 1001:Federal Bureau of Investigation 841: 332:on paper, writing a message in 3505:Information-theoretic security 2904:(pre-print, not peer reviewed) 2687:Electronic Frontier Foundation 1554: 1542: 1503: 1453: 1411:"Information Hiding: A survey" 1402: 1371: 1289: 944:from the imaging element; for 651:" book published by Springer. 254:sent a message to his vassal, 1: 3693: 2900:10.36227/techrxiv.16755457.v1 2363:ACM Wksp. Multimedia Security 1323:"Searching for the Stego Key" 1297:"Definition of STEGANOGRAPHY" 1282: 747:Countermeasures and detection 298: 244:mentions two examples in his 2512:10.1007/978-3-642-24712-5_10 1617:"Techniques for data hiding" 1602:10.1016/j.sigpro.2009.08.010 869:Example from modern practice 518:Voice over Internet Protocol 434:Images hidden in sound files 7: 4531:Intelligence cycle security 3621:Message authentication code 3576:Cryptographic hash function 3379:Cryptographic hash function 3242:, DefCon 12 (1 August 2004) 3079:. Artech House Publishers. 3039:. Artech House Publishers. 2914:Votiro (30 November 2021). 2669:10.13140/RG.2.2.21608.98561 2448:10.1007/978-3-540-88873-4_6 2334:Information Hiding Workshop 1760:, IEEE, pp. 371–375, 2008. 1630:(3.4). IBM Corp.: 313–336. 1461:"Polygraphiae (cf. p. 71f)" 1153: 627:Symposium, September 1977. 365:readers. Examples include: 323: 132:, which combines the words 10: 4856: 4789:Observer-expectancy effect 3500:Harvest now, decrypt later 2959: 2548:(1 ed.). Wiley-IEEE. 2294:Craig Rowland (May 1997). 2087:10.1016/j.cose.2021.102207 1570:, Scenario Magazine, 2013. 1253:Steganographic file system 1100:Stegoanalytical algorithms 1092: 1059: 850: 692:Security through obscurity 689: 617: 557: 530:bit-rate streaming media. 302: 209: 180:security through obscurity 20: 4749: 4716:Paranoiac-critical method 4698: 4662: 4612: 4596: 4521: 4463: 4423: 4368: 4325: 4190: 4152: 4132: 4123: 4114: 3923: 3892: 3802: 3779: 3701: 3639: 3616:Post-quantum cryptography 3568: 3309: 3271: 2720:. Twinstate Technologies. 2274:irevolution.wordpress.com 1945:"ASCII Art Steganography" 1849:10.1109/tifs.2012.2218599 1799:10.1109/tifs.2011.2108649 1682:10.1109/icip.2003.1247015 1015:Distributed steganography 283:developed his so-called " 147: 137: 3606:Quantum key distribution 3596:Authenticated encryption 3451:Random number generation 3227:16 December 2017 at the 2074:Computers & Security 936:requires. There must be 4498:Intelligence assessment 4488:All-source intelligence 4108:Intelligence management 3817:Covert listening device 3787:Intelligence assessment 3601:Public-key cryptography 3591:Symmetric-key algorithm 3384:Key derivation function 3344:Cryptographic primitive 3337:Authentication protocol 3322:Outline of cryptography 3317:History of cryptography 3214:23 October 2012 at the 2659:Wiseman, Simon (2017). 2119:10.1109/tse.1987.233153 2021:10.1145/3230833.3233261 1418:Proceedings of the IEEE 1043:alternate reality games 922:information theoretical 4182:Operational techniques 4137:Special reconnaissance 3389:Secure Hash Algorithms 3332:Cryptographic protocol 3000:Wayner, Peter (2009). 2967:Wayner, Peter (2002). 2745:10.1109/IIHMSP.2011.20 2626:Wayner, Peter (2009). 2113:. SE-13 (2): 292–296. 1085:analysis of the file. 1048:The communications of 888:For example, a 24-bit 847:Use in modern printers 836:Content Threat Removal 686:Additional terminology 606: 548:cyber-physical systems 422:Chaffing and winnowing 409: 401: 317: 313:Deciphering the code. 233: 194:message is being sent 184:Kerckhoffs's principle 37: 4066:Targeted surveillance 3495:End-to-end encryption 3441:Cryptojacking malware 1968:ACM Computing Surveys 1229:Musical Steganography 1022:U.S. patent 8,527,779 905:text for every three 898:least significant bit 853:Printer steganography 803:U.S. patent 2,445,586 797:U.S. patent 2,515,232 690:Further information: 612:printer steganography 604: 594:as such a technique. 574:. Then, an innocuous 407: 387: 312: 217: 152:) meaning "writing". 35: 4840:Espionage techniques 4503:Medical intelligence 4473:Competing hypotheses 4283:Industrial espionage 4268:Denial and deception 3992:Industrial espionage 3792:competing hypotheses 3611:Quantum cryptography 3535:Trusted timestamping 3125:improve this article 2739:. pp. 153–156. 2300:First Monday Journal 1566:14 July 2014 at the 1561:Social Steganography 1241:Security engineering 1237: – Type of code 1217:Digital watermarking 989:EURion constellation 981:digital watermarking 360:Social steganography 348:to hide messages as 340:worn by a courier, 4794:Pattern recognition 4767:Clustering illusion 4741:Visual cryptography 4536:Counterintelligence 4451:Technical (TECHINT) 4446:Open-source (OSINT) 4436:Geospatial (GEOINT) 4410:Casualty estimation 3364:Cryptographic nonce 3137:footnote references 3020:on 24 December 2010 2987:on 24 December 2010 2217:10.1007/11558859_19 2176:10.5210/fm.v2i5.528 1728:2005SPIE.5681..607D 1636:10.1147/sj.353.0313 1624:IBM Systems Journal 1594:2010SigPr..90..727C 1342:2004SPIE.5306...70F 1301:Merriam-webster.com 1270:Visual cryptography 1258:Steganography tools 1211:Deniable encryption 1050:The May Day mystery 932:than the "surface" 772:Paper Trade Journal 623:CPS steganography. 281:Johannes Trithemius 220:Johannes Trithemius 157:Johannes Trithemius 4604:Subliminal message 4508:Military geography 4493:Basic intelligence 4431:Financial (FININT) 4372:signature (MASINT) 4298:One-way voice link 4234:Concealment device 3943:Cold War espionage 3910:Front organization 3884:Surveillance tools 3862:Phone surveillance 3857:One-way voice link 3812:Concealment device 3480:Subliminal channel 3464:Pseudorandom noise 3406:Key (cryptography) 3076:Information Hiding 2689:. 16 October 2005. 2409:on 29 October 2012 2372:on 29 October 2012 2306:on 26 January 2013 2209:Information Hiding 1758:IEEE GLOBECOM 2008 1510:Newman, Lily Hay. 1173:BPCS-Steganography 1068:antivirus software 766:that would reveal 660:protocol data unit 649:Information Hiding 607: 552:Internet of Things 410: 402: 318: 234: 38: 4822: 4821: 4772:Cryptic crossword 4649:Phonetic reversal 4556: 4555: 4459: 4458: 4350:Direction finding 4340:In modern history 4321: 4320: 4074: 4073: 3728:Agent provocateur 3661: 3660: 3657: 3656: 3540:Key-based routing 3530:Trapdoor function 3396:Digital signature 3165: 3164: 3157: 3065:978-0-792-37204-2 3046:978-1-580-53035-4 3013:978-0-123-74479-1 2980:978-1-558-60769-9 2857:Maydaymystery.org 2832:Maydaymystery.org 2807:Maydaymystery.org 2754:978-1-4577-1397-2 2555:978-1-118-86169-1 2521:978-3-642-24711-8 2457:978-3-540-88872-7 2015:. pp. 1–10. 1766:978-1-4244-2324-8 1736:10.1117/12.586579 1582:Signal Processing 1350:10.1117/12.521353 1275:Security printing 1003:alleged that the 985:Coded Anti-Piracy 972:schemes (such as 970:lossy compression 753:ultraviolet light 458: 396:and a subsequent 4847: 4814:Unconscious mind 4583: 4576: 4569: 4560: 4559: 4355:Traffic analysis 4327:Signals (SIGINT) 4162:Asset recruiting 4130: 4129: 4121: 4120: 4101: 4094: 4087: 4078: 4077: 3688: 3681: 3674: 3665: 3664: 3647: 3646: 3475:Insecure channel 3327:Classical cipher 3296: 3289: 3282: 3273: 3272: 3269: 3268: 3160: 3153: 3149: 3146: 3140: 3108: 3107: 3100: 3090: 3069: 3050: 3029: 3027: 3025: 3016:. Archived from 2996: 2994: 2992: 2983:. Archived from 2953: 2952: 2950: 2948: 2937: 2931: 2930: 2928: 2926: 2911: 2905: 2903: 2893: 2877: 2868: 2867: 2865: 2863: 2849: 2843: 2842: 2840: 2838: 2824: 2818: 2817: 2815: 2813: 2799: 2793: 2792: 2790: 2788: 2773: 2767: 2766: 2728: 2722: 2721: 2714: 2708: 2707: 2705: 2697: 2691: 2690: 2679: 2673: 2672: 2656: 2650: 2649: 2637: 2631: 2624: 2615: 2614: 2612: 2610: 2601: 2592: 2586: 2585: 2583: 2581: 2566: 2560: 2559: 2539: 2533: 2532: 2530: 2528: 2497: 2491: 2490: 2488: 2476: 2470: 2469: 2441: 2425: 2419: 2418: 2416: 2414: 2408: 2402:. Archived from 2397: 2388: 2382: 2381: 2379: 2377: 2371: 2365:. Archived from 2360: 2351: 2345: 2344: 2342: 2340: 2331: 2322: 2316: 2315: 2313: 2311: 2302:. Archived from 2291: 2285: 2284: 2282: 2280: 2265: 2259: 2258: 2256: 2254: 2245: 2236: 2230: 2229: 2204: 2198: 2195: 2189: 2188: 2178: 2154: 2148: 2145: 2139: 2138: 2106: 2100: 2099: 2089: 2065: 2059: 2058: 2049: 2043: 2042: 2008: 2002: 2001: 1983: 1959: 1953: 1952: 1940: 1934: 1933: 1925: 1919: 1918: 1910: 1904: 1903: 1892:10.1002/ett.3984 1875: 1869: 1868: 1843:(6): 1865–1875. 1834: 1825: 1819: 1818: 1784: 1775: 1769: 1754: 1748: 1747: 1710: 1704: 1703: 1669: 1663: 1662: 1661:on 11 June 2020. 1660: 1654:. Archived from 1621: 1612: 1606: 1605: 1577: 1571: 1558: 1552: 1546: 1540: 1539: 1537: 1535: 1526:. Archived from 1507: 1501: 1500: 1498: 1496: 1482: 1473: 1472: 1470: 1468: 1457: 1451: 1450: 1448: 1446: 1440:10.1109/5.771065 1433: 1415: 1406: 1400: 1399: 1397: 1395: 1386:. Archived from 1375: 1369: 1368: 1366: 1364: 1327: 1318: 1312: 1311: 1309: 1307: 1293: 1178: 1081:environments or 1056:Computer malware 1033:Online challenge 1024: 879:digital pictures 805: 799: 726:encoding density 484: 472: 460: 459: 444: 380:Digital messages 285:Ave-Maria-Cipher 165:, a treatise on 151: 141: 113: 109: 104: 103: 102: 101: 94: 91: 90: 87: 84: 81: 78: 75: 72: 69: 66: 63: 60: 57: 54: 51: 4855: 4854: 4850: 4849: 4848: 4846: 4845: 4844: 4825: 4824: 4823: 4818: 4745: 4731:Sacred geometry 4694: 4658: 4608: 4592: 4590:Hidden messages 4587: 4557: 4552: 4517: 4455: 4441:Imagery (IMINT) 4419: 4380:Electro-optical 4371: 4370:Measurement and 4364: 4317: 4293:Numbers station 4222:Black operation 4186: 4148: 4110: 4105: 4075: 4070: 4044:Sting operation 3953:Black operation 3919: 3915:Limited hangout 3897: 3888: 3852:Numbers station 3804: 3798: 3775: 3715: 3697: 3692: 3662: 3653: 3635: 3564: 3305: 3300: 3229:Wayback Machine 3216:Wayback Machine 3161: 3150: 3144: 3141: 3122: 3113:This section's 3109: 3105: 3098: 3093: 3087: 3066: 3047: 3023: 3021: 3014: 2990: 2988: 2981: 2962: 2957: 2956: 2946: 2944: 2943:. 12 April 2022 2939: 2938: 2934: 2924: 2922: 2912: 2908: 2878: 2871: 2861: 2859: 2851: 2850: 2846: 2836: 2834: 2828:"Recent things" 2826: 2825: 2821: 2811: 2809: 2801: 2800: 2796: 2786: 2784: 2774: 2770: 2755: 2729: 2725: 2716: 2715: 2711: 2703: 2699: 2698: 2694: 2681: 2680: 2676: 2657: 2653: 2638: 2634: 2625: 2618: 2608: 2606: 2599: 2593: 2589: 2579: 2577: 2567: 2563: 2556: 2540: 2536: 2526: 2524: 2522: 2498: 2494: 2477: 2473: 2458: 2426: 2422: 2412: 2410: 2406: 2395: 2389: 2385: 2375: 2373: 2369: 2358: 2352: 2348: 2338: 2336: 2329: 2323: 2319: 2309: 2307: 2292: 2288: 2278: 2276: 2266: 2262: 2252: 2250: 2243: 2237: 2233: 2227: 2205: 2201: 2196: 2192: 2155: 2151: 2146: 2142: 2107: 2103: 2066: 2062: 2050: 2046: 2031: 2009: 2005: 1990:10.1145/2684195 1960: 1956: 1941: 1937: 1926: 1922: 1911: 1907: 1876: 1872: 1832: 1826: 1822: 1782: 1776: 1772: 1755: 1751: 1711: 1707: 1692: 1670: 1666: 1658: 1619: 1613: 1609: 1578: 1574: 1568:Wayback Machine 1559: 1555: 1547: 1543: 1533: 1531: 1508: 1504: 1494: 1492: 1484: 1483: 1476: 1466: 1464: 1459: 1458: 1454: 1444: 1442: 1431:10.1.1.333.9397 1413: 1407: 1403: 1393: 1391: 1390:on 16 July 2007 1376: 1372: 1362: 1360: 1325: 1319: 1315: 1305: 1303: 1295: 1294: 1290: 1285: 1280: 1264:Audio watermark 1235:Polybius square 1176: 1156: 1139: 1110: 1102: 1097: 1091: 1064: 1058: 1035: 1020: 1017: 997: 928:must have more 871: 859:Hewlett-Packard 855: 849: 844: 801: 795: 749: 694: 688: 620: 560: 544: 514: 509: 508: 507: 506: 505: 496:Nine Inch Nails 485: 477: 476: 473: 465: 464: 461: 453: 449: 448: 445: 436: 435: 426:Mimic functions 394:color component 382: 362: 326: 307: 301: 212: 111: 107: 97: 96: 48: 44: 30: 17: 12: 11: 5: 4853: 4843: 4842: 4837: 4820: 4819: 4817: 4816: 4811: 4806: 4801: 4796: 4791: 4786: 4781: 4780: 4779: 4769: 4764: 4762:Asemic writing 4759: 4753: 4751: 4747: 4746: 4744: 4743: 4738: 4733: 4728: 4723: 4718: 4713: 4708: 4702: 4700: 4696: 4695: 4693: 4692: 4687: 4682: 4677: 4672: 4666: 4664: 4660: 4659: 4657: 4656: 4654:Reverse speech 4651: 4646: 4645: 4644: 4639: 4629: 4628: 4627: 4616: 4614: 4610: 4609: 4607: 4606: 4600: 4598: 4594: 4593: 4586: 4585: 4578: 4571: 4563: 4554: 4553: 4551: 4550: 4545: 4544: 4543: 4533: 4527: 4525: 4519: 4518: 4516: 4515: 4510: 4505: 4500: 4495: 4490: 4485: 4480: 4478:Target-centric 4475: 4469: 4467: 4461: 4460: 4457: 4456: 4454: 4453: 4448: 4443: 4438: 4433: 4427: 4425: 4421: 4420: 4418: 4417: 4407: 4402: 4400:Radiofrequency 4397: 4392: 4387: 4382: 4376: 4374: 4366: 4365: 4363: 4362: 4357: 4352: 4347: 4342: 4337: 4331: 4329: 4323: 4322: 4319: 4318: 4316: 4315: 4310: 4305: 4300: 4295: 4290: 4285: 4280: 4275: 4270: 4265: 4256: 4251: 4246: 4241: 4236: 4231: 4230: 4229: 4219: 4214: 4213: 4212: 4207: 4196: 4194: 4188: 4187: 4185: 4184: 4179: 4174: 4169: 4164: 4158: 4156: 4150: 4149: 4147: 4146: 4145: 4144: 4133: 4127: 4125:Human (HUMINT) 4118: 4112: 4111: 4104: 4103: 4096: 4089: 4081: 4072: 4071: 4069: 4068: 4063: 4062: 4061: 4056: 4046: 4041: 4036: 4031: 4026: 4021: 4016: 4011: 4010: 4009: 4004: 3994: 3989: 3984: 3983: 3982: 3977: 3967: 3966: 3965: 3960: 3950: 3945: 3940: 3939: 3938: 3927: 3925: 3921: 3920: 3918: 3917: 3912: 3907: 3901: 3899: 3890: 3889: 3887: 3886: 3881: 3880: 3879: 3869: 3864: 3859: 3854: 3849: 3844: 3839: 3834: 3829: 3824: 3819: 3814: 3808: 3806: 3805:communications 3800: 3799: 3797: 3796: 3795: 3794: 3783: 3781: 3777: 3776: 3774: 3773: 3768: 3763: 3758: 3753: 3748: 3743: 3742: 3741: 3731: 3724: 3722:Agent handling 3718: 3716: 3714: 3713: 3708: 3702: 3699: 3698: 3691: 3690: 3683: 3676: 3668: 3659: 3658: 3655: 3654: 3652: 3651: 3640: 3637: 3636: 3634: 3633: 3628: 3626:Random numbers 3623: 3618: 3613: 3608: 3603: 3598: 3593: 3588: 3583: 3578: 3572: 3570: 3566: 3565: 3563: 3562: 3557: 3552: 3550:Garlic routing 3547: 3542: 3537: 3532: 3527: 3522: 3517: 3512: 3507: 3502: 3497: 3492: 3487: 3482: 3477: 3472: 3470:Secure channel 3467: 3461: 3460: 3459: 3448: 3443: 3438: 3433: 3428: 3426:Key stretching 3423: 3418: 3413: 3408: 3403: 3398: 3393: 3392: 3391: 3386: 3381: 3371: 3369:Cryptovirology 3366: 3361: 3356: 3354:Cryptocurrency 3351: 3346: 3341: 3340: 3339: 3329: 3324: 3319: 3313: 3311: 3307: 3306: 3299: 3298: 3291: 3284: 3276: 3266: 3265: 3259: 3249: 3243: 3237: 3232: 3219: 3206: 3197:2002 paper by 3192: 3186: 3181: 3172: 3163: 3162: 3117:external links 3112: 3110: 3103: 3097: 3096:External links 3094: 3092: 3091: 3086:978-1608079285 3085: 3070: 3064: 3051: 3045: 3030: 3012: 2997: 2979: 2963: 2961: 2958: 2955: 2954: 2932: 2906: 2869: 2844: 2819: 2794: 2768: 2753: 2723: 2709: 2692: 2674: 2651: 2632: 2616: 2587: 2561: 2554: 2534: 2520: 2492: 2471: 2456: 2420: 2383: 2346: 2317: 2286: 2260: 2231: 2225: 2199: 2190: 2149: 2140: 2101: 2060: 2044: 2029: 2003: 1954: 1935: 1920: 1905: 1870: 1820: 1793:(2): 296–306. 1770: 1749: 1705: 1690: 1664: 1607: 1588:(3): 727–752. 1572: 1553: 1541: 1530:on 8 June 2022 1502: 1474: 1452: 1424:(7): 1062–78. 1401: 1370: 1313: 1287: 1286: 1284: 1281: 1279: 1278: 1272: 1267: 1261: 1255: 1250: 1244: 1238: 1232: 1226: 1220: 1214: 1208: 1202: 1199:Covert channel 1196: 1193:Warrant canary 1190: 1184: 1179: 1170: 1164: 1157: 1155: 1152: 1151: 1150: 1147: 1138: 1135: 1134: 1133: 1130: 1127: 1124: 1121: 1118: 1109: 1106: 1101: 1098: 1093:Main article: 1090: 1087: 1060:Main article: 1057: 1054: 1034: 1031: 1016: 1013: 996: 993: 870: 867: 851:Main article: 848: 845: 843: 840: 748: 745: 722:covert message 687: 684: 683: 682: 679: 619: 616: 592:Bacon's cipher 559: 556: 543: 540: 513: 510: 486: 479: 478: 474: 467: 466: 462: 451: 450: 446: 439: 438: 437: 433: 432: 431: 430: 381: 378: 377: 376: 373: 370: 361: 358: 325: 322: 315:Steganographia 303:Main article: 300: 297: 225:Steganographia 211: 208: 198:its contents. 162:Steganographia 130:steganographia 15: 9: 6: 4: 3: 2: 4852: 4841: 4838: 4836: 4835:Steganography 4833: 4832: 4830: 4815: 4812: 4810: 4809:Synchronicity 4807: 4805: 4802: 4800: 4797: 4795: 4792: 4790: 4787: 4785: 4782: 4778: 4775: 4774: 4773: 4770: 4768: 4765: 4763: 4760: 4758: 4755: 4754: 4752: 4748: 4742: 4739: 4737: 4736:Steganography 4734: 4732: 4729: 4727: 4724: 4722: 4719: 4717: 4714: 4712: 4709: 4707: 4704: 4703: 4701: 4697: 4691: 4688: 4686: 4683: 4681: 4678: 4676: 4673: 4671: 4668: 4667: 4665: 4661: 4655: 4652: 4650: 4647: 4643: 4640: 4638: 4635: 4634: 4633: 4630: 4626: 4623: 4622: 4621: 4618: 4617: 4615: 4611: 4605: 4602: 4601: 4599: 4595: 4591: 4584: 4579: 4577: 4572: 4570: 4565: 4564: 4561: 4549: 4546: 4542: 4541:organizations 4539: 4538: 4537: 4534: 4532: 4529: 4528: 4526: 4524: 4523:Dissemination 4520: 4514: 4511: 4509: 4506: 4504: 4501: 4499: 4496: 4494: 4491: 4489: 4486: 4484: 4481: 4479: 4476: 4474: 4471: 4470: 4468: 4466: 4462: 4452: 4449: 4447: 4444: 4442: 4439: 4437: 4434: 4432: 4429: 4428: 4426: 4422: 4415: 4411: 4408: 4406: 4403: 4401: 4398: 4396: 4393: 4391: 4388: 4386: 4383: 4381: 4378: 4377: 4375: 4373: 4367: 4361: 4358: 4356: 4353: 4351: 4348: 4346: 4343: 4341: 4338: 4336: 4333: 4332: 4330: 4328: 4324: 4314: 4311: 4309: 4308:Steganography 4306: 4304: 4301: 4299: 4296: 4294: 4291: 4289: 4288:Interrogation 4286: 4284: 4281: 4279: 4276: 4274: 4273:Eavesdropping 4271: 4269: 4266: 4264: 4260: 4257: 4255: 4252: 4250: 4247: 4245: 4242: 4240: 4237: 4235: 4232: 4228: 4225: 4224: 4223: 4220: 4218: 4215: 4211: 4208: 4206: 4203: 4202: 4201: 4198: 4197: 4195: 4193: 4189: 4183: 4180: 4178: 4177:Direct action 4175: 4173: 4172:Covert action 4170: 4168: 4165: 4163: 4160: 4159: 4157: 4155: 4151: 4143: 4142:organizations 4140: 4139: 4138: 4135: 4134: 4131: 4128: 4126: 4122: 4119: 4117: 4113: 4109: 4102: 4097: 4095: 4090: 4088: 4083: 4082: 4079: 4067: 4064: 4060: 4057: 4055: 4052: 4051: 4050: 4047: 4045: 4042: 4040: 4037: 4035: 4032: 4030: 4027: 4025: 4022: 4020: 4017: 4015: 4012: 4008: 4005: 4003: 4002:interrogation 4000: 3999: 3998: 3995: 3993: 3990: 3988: 3985: 3981: 3978: 3976: 3973: 3972: 3971: 3970:Eavesdropping 3968: 3964: 3961: 3959: 3956: 3955: 3954: 3951: 3949: 3946: 3944: 3941: 3937: 3934: 3933: 3932: 3929: 3928: 3926: 3922: 3916: 3913: 3911: 3908: 3906: 3903: 3902: 3900: 3895: 3891: 3885: 3882: 3878: 3875: 3874: 3873: 3872:Steganography 3870: 3868: 3865: 3863: 3860: 3858: 3855: 3853: 3850: 3848: 3847:Invisible ink 3845: 3843: 3840: 3838: 3835: 3833: 3830: 3828: 3825: 3823: 3820: 3818: 3815: 3813: 3810: 3809: 3807: 3801: 3793: 3790: 3789: 3788: 3785: 3784: 3782: 3778: 3772: 3769: 3767: 3766:Sleeper agent 3764: 3762: 3759: 3757: 3754: 3752: 3749: 3747: 3744: 3740: 3737: 3736: 3735: 3732: 3730: 3729: 3725: 3723: 3720: 3719: 3717: 3712: 3709: 3707: 3704: 3703: 3700: 3696: 3689: 3684: 3682: 3677: 3675: 3670: 3669: 3666: 3650: 3642: 3641: 3638: 3632: 3631:Steganography 3629: 3627: 3624: 3622: 3619: 3617: 3614: 3612: 3609: 3607: 3604: 3602: 3599: 3597: 3594: 3592: 3589: 3587: 3586:Stream cipher 3584: 3582: 3579: 3577: 3574: 3573: 3571: 3567: 3561: 3558: 3556: 3553: 3551: 3548: 3546: 3545:Onion routing 3543: 3541: 3538: 3536: 3533: 3531: 3528: 3526: 3525:Shared secret 3523: 3521: 3518: 3516: 3513: 3511: 3508: 3506: 3503: 3501: 3498: 3496: 3493: 3491: 3488: 3486: 3483: 3481: 3478: 3476: 3473: 3471: 3468: 3465: 3462: 3457: 3454: 3453: 3452: 3449: 3447: 3444: 3442: 3439: 3437: 3434: 3432: 3429: 3427: 3424: 3422: 3419: 3417: 3416:Key generator 3414: 3412: 3409: 3407: 3404: 3402: 3399: 3397: 3394: 3390: 3387: 3385: 3382: 3380: 3377: 3376: 3375: 3374:Hash function 3372: 3370: 3367: 3365: 3362: 3360: 3357: 3355: 3352: 3350: 3349:Cryptanalysis 3347: 3345: 3342: 3338: 3335: 3334: 3333: 3330: 3328: 3325: 3323: 3320: 3318: 3315: 3314: 3312: 3308: 3304: 3297: 3292: 3290: 3285: 3283: 3278: 3277: 3274: 3270: 3263: 3260: 3258:Kyiv, Ukraine 3257: 3253: 3250: 3247: 3244: 3241: 3238: 3236: 3233: 3230: 3226: 3223: 3220: 3217: 3213: 3210: 3207: 3204: 3200: 3196: 3193: 3190: 3187: 3185: 3182: 3180: 3176: 3175:Steganography 3173: 3170: 3167: 3166: 3159: 3156: 3148: 3138: 3134: 3133:inappropriate 3130: 3126: 3120: 3118: 3111: 3102: 3101: 3088: 3082: 3078: 3077: 3071: 3067: 3061: 3057: 3052: 3048: 3042: 3038: 3037: 3031: 3019: 3015: 3009: 3005: 3004: 2998: 2986: 2982: 2976: 2972: 2971: 2965: 2964: 2942: 2936: 2921: 2917: 2910: 2901: 2897: 2892: 2887: 2883: 2876: 2874: 2858: 2854: 2853:"The Mystery" 2848: 2833: 2829: 2823: 2808: 2804: 2798: 2783: 2779: 2772: 2764: 2760: 2756: 2750: 2746: 2742: 2738: 2734: 2727: 2719: 2713: 2702: 2696: 2688: 2684: 2678: 2670: 2666: 2662: 2655: 2647: 2643: 2636: 2629: 2623: 2621: 2605: 2598: 2591: 2576: 2575:IEEE Spectrum 2572: 2565: 2557: 2551: 2547: 2546: 2538: 2523: 2517: 2513: 2509: 2505: 2504: 2496: 2487: 2482: 2475: 2467: 2463: 2459: 2453: 2449: 2445: 2440: 2435: 2431: 2424: 2405: 2401: 2394: 2387: 2368: 2364: 2357: 2350: 2335: 2328: 2321: 2305: 2301: 2297: 2290: 2275: 2271: 2264: 2249: 2242: 2235: 2228: 2226:9783540290391 2222: 2218: 2214: 2210: 2203: 2194: 2186: 2182: 2177: 2172: 2168: 2164: 2160: 2153: 2144: 2136: 2132: 2128: 2124: 2120: 2116: 2112: 2105: 2097: 2093: 2088: 2083: 2079: 2075: 2071: 2064: 2056: 2048: 2040: 2036: 2032: 2030:9781450364485 2026: 2022: 2018: 2014: 2007: 1999: 1995: 1991: 1987: 1982: 1977: 1973: 1969: 1965: 1958: 1950: 1946: 1943:Vincent Chu. 1939: 1931: 1924: 1916: 1909: 1901: 1897: 1893: 1889: 1885: 1881: 1874: 1866: 1862: 1858: 1854: 1850: 1846: 1842: 1838: 1831: 1824: 1816: 1812: 1808: 1804: 1800: 1796: 1792: 1788: 1781: 1774: 1767: 1763: 1759: 1753: 1745: 1741: 1737: 1733: 1729: 1725: 1722:. SPIE: 607. 1721: 1717: 1709: 1701: 1697: 1693: 1687: 1683: 1679: 1675: 1668: 1657: 1653: 1649: 1645: 1641: 1637: 1633: 1629: 1625: 1618: 1611: 1603: 1599: 1595: 1591: 1587: 1583: 1576: 1569: 1565: 1562: 1557: 1550: 1545: 1529: 1525: 1521: 1517: 1513: 1506: 1491: 1487: 1481: 1479: 1462: 1456: 1441: 1437: 1432: 1427: 1423: 1419: 1412: 1405: 1389: 1385: 1381: 1374: 1359: 1355: 1351: 1347: 1343: 1339: 1335: 1331: 1324: 1317: 1302: 1298: 1292: 1288: 1276: 1273: 1271: 1268: 1265: 1262: 1259: 1256: 1254: 1251: 1248: 1245: 1242: 1239: 1236: 1233: 1230: 1227: 1224: 1223:Invisible ink 1221: 1218: 1215: 1212: 1209: 1206: 1203: 1200: 1197: 1194: 1191: 1188: 1185: 1183: 1180: 1174: 1171: 1168: 1165: 1162: 1161:40-track mode 1159: 1158: 1148: 1144: 1143: 1142: 1131: 1128: 1125: 1122: 1119: 1116: 1115: 1114: 1105: 1096: 1086: 1084: 1083:deep learning 1080: 1076: 1071: 1069: 1063: 1053: 1051: 1046: 1044: 1040: 1030: 1028: 1027:Chuck Easttom 1023: 1012: 1008: 1006: 1002: 999:In 2010, the 992: 990: 986: 982: 977: 975: 971: 967: 963: 962:flicker noise 959: 958:thermal noise 955: 954:analog signal 951: 950:amplification 947: 946:digital audio 943: 939: 935: 931: 927: 923: 918: 916: 910: 908: 904: 899: 895: 891: 886: 884: 880: 876: 866: 864: 860: 854: 839: 837: 833: 827: 823: 820: 814: 812: 807: 804: 798: 793: 789: 785: 781: 777: 773: 769: 768:invisible ink 765: 761: 756: 754: 744: 742: 738: 734: 729: 727: 723: 719: 715: 711: 707: 703: 698: 693: 680: 676: 675:Voice-over-IP 672: 671: 670: 667: 663: 661: 656: 652: 650: 645: 642: 639: 636: 634: 628: 624: 615: 614:for details. 613: 603: 599: 595: 593: 589: 588:Francis Bacon 585: 581: 577: 573: 572: 567: 566: 555: 553: 549: 539: 537: 531: 527: 524: 521: 519: 503: 502: 497: 493: 489: 483: 471: 443: 429: 427: 423: 418: 416: 406: 399: 398:normalization 395: 391: 386: 374: 371: 368: 367: 366: 357: 355: 351: 350:musical notes 347: 344:, or using a 343: 339: 335: 331: 330:invisible ink 321: 316: 311: 306: 296: 294: 290: 286: 282: 279: 277: 271: 269: 265: 261: 257: 253: 249: 248: 243: 239: 231: 227: 226: 221: 218:A chart from 216: 207: 205: 199: 197: 192: 187: 185: 181: 178:are forms of 177: 176:shared secret 173: 172:invisible ink 168: 164: 163: 158: 153: 150: 145: 140: 135: 131: 128: 124: 123:steganography 120: 119:computer file 116: 115: 100: 93: 42: 41:Steganography 34: 28: 24: 19: 4735: 4632:Hidden track 4313:Surveillance 4307: 4303:Resident spy 4244:Cryptography 4049:Surveillance 3871: 3837:Cyber spying 3822:Cryptography 3761:Resident spy 3746:Double agent 3726: 3630: 3581:Block cipher 3421:Key schedule 3411:Key exchange 3401:Kleptography 3359:Cryptosystem 3303:Cryptography 3255: 3202: 3199:Niels Provos 3151: 3142: 3127:by removing 3114: 3075: 3058:. Springer. 3055: 3035: 3022:. Retrieved 3018:the original 3002: 2989:. Retrieved 2985:the original 2969: 2945:. Retrieved 2935: 2923:. Retrieved 2919: 2909: 2860:. Retrieved 2856: 2847: 2835:. Retrieved 2831: 2822: 2810:. Retrieved 2806: 2797: 2785:. Retrieved 2781: 2771: 2732: 2726: 2712: 2695: 2677: 2654: 2635: 2627: 2607:. Retrieved 2603: 2590: 2578:. Retrieved 2574: 2564: 2544: 2537: 2525:. Retrieved 2502: 2495: 2474: 2429: 2423: 2411:. Retrieved 2404:the original 2399: 2386: 2374:. Retrieved 2367:the original 2362: 2349: 2337:. Retrieved 2333: 2320: 2308:. Retrieved 2304:the original 2299: 2289: 2277:. Retrieved 2273: 2263: 2251:. Retrieved 2247: 2234: 2208: 2202: 2193: 2166: 2163:First Monday 2162: 2152: 2143: 2110: 2104: 2077: 2073: 2063: 2054: 2047: 2012: 2006: 1971: 1967: 1957: 1948: 1938: 1929: 1923: 1914: 1908: 1883: 1879: 1873: 1840: 1836: 1823: 1790: 1786: 1773: 1757: 1752: 1719: 1715: 1708: 1673: 1667: 1656:the original 1627: 1623: 1610: 1585: 1581: 1575: 1556: 1544: 1532:. Retrieved 1528:the original 1515: 1505: 1493:. Retrieved 1489: 1465:. Retrieved 1455: 1443:. Retrieved 1421: 1417: 1404: 1392:. Retrieved 1388:the original 1373: 1361:. Retrieved 1333: 1329: 1316: 1304:. Retrieved 1300: 1291: 1205:Cryptography 1140: 1111: 1103: 1095:Steganalysis 1089:Steganalysis 1072: 1065: 1062:Stegomalware 1047: 1036: 1018: 1009: 998: 978: 919: 911: 887: 872: 856: 842:Applications 831: 828: 824: 819:steganalysis 815: 811:steganalysis 808: 787: 783: 779: 771: 760:World War II 757: 750: 740: 736: 732: 730: 725: 721: 717: 713: 709: 705: 701: 699: 695: 668: 664: 657: 653: 648: 646: 643: 640: 637: 632: 629: 625: 621: 608: 596: 579: 575: 569: 563: 561: 545: 535: 532: 528: 525: 522: 515: 504:album (2007) 499: 492:hidden image 419: 415:one-time pad 411: 363: 346:music cipher 327: 319: 314: 292: 288: 276:Polygraphiae 274: 273:In his work 272: 245: 235: 223: 200: 195: 188: 167:cryptography 160: 154: 143: 133: 129: 122: 40: 39: 18: 4711:Hidden text 4642:pregap list 4620:Backmasking 4385:Geophysical 4167:Cell system 4154:Clandestine 4039:Stay-behind 3948:Recruitment 3905:Canary trap 3803:Devices and 3751:Field agent 3569:Mathematics 3560:Mix network 2862:23 November 2837:23 November 2812:23 November 2803:"The texts" 2609:11 February 2580:11 February 2527:4 September 1974:(3): 1–26. 1445:2 September 1394:2 September 1306:14 December 1187:Canary trap 1039:Cicada 3301 915:noise floor 488:Spectrogram 354:sheet music 256:Aristagoras 230:Dr John Dee 125:comes from 23:Stenography 4829:Categories 4804:Simulacrum 4799:Palindrome 4784:Easter egg 4726:Psychorama 4721:Pareidolia 4690:Cryptology 4685:Bible code 4680:Theomatics 4675:Numerology 4670:Chronogram 4414:earthquake 4278:False flag 4116:Collection 4034:Sexpionage 4014:COINTELPRO 4007:safe house 3987:False flag 3924:Operations 3898:techniques 3894:Tradecraft 3520:Ciphertext 3490:Decryption 3485:Encryption 3446:Ransomware 3024:4 November 2991:4 November 2947:11 January 2925:11 January 2891:2110.02504 2884:(Report). 2787:11 January 2663:(Report). 2080:: 102207. 1691:0780377508 1363:23 January 1283:References 1182:Camera/Shy 966:shot noise 938:redundancy 718:stego file 590:developed 576:cover text 571:ciphertext 550:(CPS)/the 334:Morse code 299:Techniques 264:wax tablet 228:copied by 4757:Apophenia 4405:Materials 4259:Defection 4254:Dead drop 4227:black bag 4192:Espionage 3958:black bag 3842:Dead drop 3771:Spymaster 3695:Espionage 3510:Plaintext 3129:excessive 2486:1005.1925 2439:0805.2938 2185:1396-0466 2127:0098-5589 2096:232342523 1981:1406.2901 1900:225866797 1857:1556-6013 1807:1556-6013 1744:206413447 1644:0018-8670 1524:1059-1028 1426:CiteSeerX 1336:: 70–82. 1247:Semiotics 788:Coatalith 780:Sensicoat 741:candidate 580:stegotext 565:plaintext 501:Year Zero 498:from the 342:microdots 293:VICIPEDIA 268:shorthand 260:Demaratus 252:Histiaeus 247:Histories 242:Herodotus 191:encrypted 4465:Analysis 4263:Turncoat 4210:handling 4024:SHAMROCK 3877:microdot 3780:Analysis 3649:Category 3555:Kademlia 3515:Codetext 3458:(CSPRNG) 3436:Machines 3256:MK-Press 3225:Archived 3212:Archived 3145:May 2024 2782:BBC News 2763:17769131 2466:14336157 2039:51976841 1998:14654993 1865:16539562 1815:15096702 1652:16672162 1564:Archived 1384:AlterNet 1167:Acrostic 1154:See also 930:capacity 920:From an 883:Internet 832:Stegware 733:suspects 584:typeface 520:(VoIP). 392:of each 324:Physical 144:-graphia 139:στεγανός 134:steganós 4777:Anagram 4663:Numeric 4412: ( 4390:Nuclear 4360:TEMPEST 4019:MINARET 3963:wetwork 3310:General 3262:stegano 3123:Please 3115:use of 2960:Sources 2413:16 June 2376:16 June 2339:16 June 2310:16 June 2279:17 June 2253:17 June 2135:3042941 1917:. 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