DES Calculator

You can use the DES Calculator applet displayed below to encrypt or decrypt using DES the specified 64-bit (16 hex digit) data value with the 64-bit (16 hex digit) key, with a trace of the calculations. To use the calculator fill in the Input Data value (being 16 hexadecimal digits), and the DES Key (being 32 hexadecimal digits), and press either the Encrypt or Decrypt button, as required. The resulting value will be displayed, along with the trace of the calculation, at the level of detail specified by te Trace Level radio buttons. If there is an error in the supplied values, an error message will be displayed in red.

An example DES test value, taken from "H. Katzan, The Standard Data Encryption Algorithm, pp75-94, Petrocelli Books Inc., New York, 1977" is:

Key:        5B5A57676A56676E
Plaintext:  675A69675E5A6B5A
Ciphertext: 974AFFBF86022D1F

Encrypting the plaintext with the key should give the ciphertext, decrypting the ciphertext with the key should give the plaintext.