It is the implementation of DES (only for learning purposes). DES (Data Encryption Standard) is a Symmetrica-key Encryption Algorithm. It is a Block cipher. It encrypts data of 64 bits block with a key of 56 bits (extracted from 64 bits). The same algorithm is used for both encryption and decryption.
# ./bin/des -e message key
# ./bin/des -d message key
Please enter exact 64 bits key.
Enhance support for message greater than 64 bits.
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