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Should One Test For Weak Keys In Des? |
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Answer» Since there are 256 POSSIBLE DES keys the chance of PICKING a weak or semi-weak key at random is 2-52. As long as the user-provided key is chosen ENTIRELY at random, they can be safely ignored when DES is used for ENCRYPTION. Despite this, some users prefer to test whether a key to be used for DES encryption is in fact a weak key. Such a test will have no SIGNIFICANT impact on the time required for encryption. Since there are 256 possible DES keys the chance of picking a weak or semi-weak key at random is 2-52. As long as the user-provided key is chosen entirely at random, they can be safely ignored when DES is used for encryption. Despite this, some users prefer to test whether a key to be used for DES encryption is in fact a weak key. Such a test will have no significant impact on the time required for encryption. |
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