Briefly Describe DES and Its Variants

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The Answer is The data encryption standard (DES), dating back to 1976, is a cipher selected as an official federal information processing standard (FIPS) for the United States. It is certainly the most widely used cipher internationally. It uses fixed 64-bit blocks and 64-bit keys with 8- bits parity. The 54-bit key (64 - 8) is generally considered too small, and some DES keys have been broken in less than 24 hours. Most DES users now use Triple DES (3DES). In 3DES, data is encrypted with DES to produce ciphertext, and then a second key is used to "decrypt" the ciphertext. Finally, the data is encrypted again with either the original key (two-key 3DES) or with a third key (three-key 3DES). 3DES is secure but slow. A quicker alternative is DES-X, which increases the key size by XORing extra key material before and after DES.

Briefly Describe DES and Its Variants

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