Firewalls White Papers
Cryptography is Not the Ultimate Solution
Overview The history of cryptography goes back almost as far as the beginning of written history itself. Substitution cyphers, where one letter or token gets substituted by another, were used by the ancient Greeks. Cryptography and the breaking of codes were critical factors in the naval, air and sea battles of World War II.Older cryptographic engines, like the Enigma, relied on the use of symmetric key cryptography: both the sender and the receiver used the same key, or machine setup. The simplest mechansim for a symmetric key cipher is to exclusive OR the text you want to hide with a key. When the end of the key is reached, you start with the beginning of the key again, as if the key were a wheel that was applied to the stream of data as it passed. This method of using XOR provides trivially broken encryption. Some modern ciphers, like RC4, use the XOR mechanism, but use the key to make a much more complicated and changing "wheel" for the encryption.
| Publisher | Spirit.com | File Format | HTML |
|---|---|---|---|
| Date Published | December 1999 | Downloads | 3 |
| Format | White Papers | ||
| Topics | |||
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