Problems with Symmetric Algorithms

One big issue with using symmetric algorithms is the key exchange problem, which can present a classic catch-22. The other main issue is the problem of trust between two parties that share a secret symmetric key. Problems of trust may be encountered when encryption is used for authentication and integrity checking. As we saw in Chapter 3, a symmetric key can be used to verify the identity of the other communicating party, but as we will now see, this requires that one party trust the other.

The Key Exchange Problem

The key exchange problem arises from the fact that communicating parties must somehow share a secret key before any secure communication can be initiated, and both parties must then ensure that the ...

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