SHACAL
| SHACAL | |
|---|---|
| developer | Helena Glove, David Naccache |
| Derived from | SHA-1 , SHA-256 |
| Certification | NESSIE (SHACAL-2) |
| Key length | 128 to 512 bits |
| Block size | 160 bit (SHACAL-1), 256 bit (SHACAL-2) |
| structure | Hash function |
| Round | 80 (SHACAL-1), 64 (SHACAL-2) |
SHACAL-1 and SHACAL-2 are symmetrical block ciphers with a variable key length from 128 bits to 512 bits, based on the hash algorithms of the SHA family . The SHACAL algorithms were designed by Helena Handschuh and David Naccache, both employees of the chip card manufacturer Gemplus .
SHACAL-1 (originally only SHACAL) is a 160-bit block encryption based on the hash method SHA-1. SHACAL-2 is a 256-bit block encryption based on the SHA-256 hash method. Based on the respective hash method, the key replaces the message and the text to be encrypted replaces the initialization values of the hash function. In order to make the function reversible for the decryption, the last step of the addition, which ensures the fixed length of the hash value, is also omitted.
The recommended minimum length for the key is 128 bits, the maximum possible length is 512 bits. When using keys with less than 512 bits, the missing positions are filled with zeros so that the length of 512 bits is reached.
In 2003, SHACAL-2 was selected as one of their 17 recommended algorithms by the NESSIE project.
Web links
- SHACAL (English, PDF; 152 kB)