Encrypt or decrypt test data values using IDEA block cipher. The IDEA Calculator applet is used to encrypt or decrypt test data values using IDEA block cipher. It takes a 64-bit (16 hex digit) data value and a 128-bit (32 hex digit) key. It can optionally provide a trace of the calculations performed, with varying degrees of detail.

To use the calculator fill in the Input Data value (being 16 hexadecimal digits), and the IDEA 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.

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

The provides details of:
1. the 128-bit (32 hex digit) key used (should be same as specified)
2. the 64-bit (16 hex digit) data value used (should be same as specified), and whether encrypt or decrypt has been requested
3. for each of the 8 rounds and output transformation - the 64-bit (16 hex digit) data value and the six 16-bit (4 hex digit) subkeys used in that round
4. and the final value computed (being the en/decrypted original data value) as shown as the result

Requirements:
* Java

The license of this software is Freeware, you can free download and free use this calculator software.