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algorithms do not evade the problem either. That a public key can be known by all without compromising the security of an encryption algorithm (for some such algorithms, though not for all) is certainly useful, but does not prevent some kinds of attacks. For example, a spoofing attack in which public
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is used to solve the problem of authenticating the keys of a person (say "person A") that some other person ("person B") is talking to or trying to talk to. In other words, it is the process of assuring that the key of "person A", held by "person B", does in fact belong to "person A" and vice versa.
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The simplest solution for this kind of problem is for the two concerned users to communicate and exchange keys. However, for systems in which there are a large number of users or in which the users do not personally know each other (e.g., Internet shopping), this is not practical. There are various
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service, if you will. Such CAs can be private organizations providing such assurances, or government agencies, or some combination of the two. However, in a significant sense, this merely moves the key authentication problem back one level for any CA may make a good faith certification of some key
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but, through error or malice, be mistaken. Any reliance on a defective key certificate 'authenticating' a public key will cause problems. As a result, many people find all PKI designs unacceptably insecure.
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This is usually done after the keys have been shared among the two sides over some secure channel. However, some algorithms share the keys at the time of authentication.
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who is trying to read or spoof the communication. There are various algorithms used now-a-days to prevent such attacks. The most common among the algorithms are
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algorithms for both symmetric keys and asymmetric public key cryptography to solve this problem.
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is claimed publicly to be that of user Alice, but is in fact a public key belonging to
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Accordingly, key authentication methods are being actively researched.
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cryptography, this is the problem of assuring that there is no
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Tanenbaum, Andrew S.; Wetherall, David J. (7 October 2010).
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The most common solution to this problem is the use of
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46:. Unsourced material may be challenged and removed.
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199:and certificate authorities (CAs) for them in a
361:Kerberos: The Network Authentication Protocol
140:For key authentication using the traditional
172:Authentication using Public Key Cryptography
164:. Other methods that can be used include
106:Learn how and when to remove this message
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166:Password-authenticated key agreement
44:adding citations to reliable sources
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366:Kerberos Authentication explained
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136:Authentication using Shared Keys
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356:Honest Achmed asks for trust
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150:Diffie–Hellman key exchange
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187:man-in-the-middle attacker
162:Needham–Schroeder protocol
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261:Identity based encryption
230:Public-key infrastructure
201:public-key infrastructure
302:Transport Layer Security
236:Public-key cryptography
197:public key certificates
154:Key distribution center
152:, authentication using
307:Threshold cryptosystem
287:Public key fingerprint
241:Key-agreement protocol
122:/Config-authentication
256:ID-based cryptography
251:Certificate authority
205:certificate authority
176:Crypto systems using
292:Quantum cryptography
55:"Key authentication"
40:improve this article
277:Pretty Good Privacy
209:digital signatures
203:(PKI) system. The
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96:November 2023
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51:Find sources:
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297:Secure Shell
282:Pseudonymity
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38:Please help
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331:. Pearson.
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267:Key escrow
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223:See also
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213:notary
190:Mallet
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