An implementation of KeeLoq encryption/decryption in Go programming language.
KeeLoq is a proprietary block cipher owned by Microchip, developed for code-hopping remote key entry (RKE) devices such as:
and is used in remote key-less entry systems from several car manufacturers - such as Chrysler, Fiat, GM, Honda, Toyota, Volvo, VW, Jaguar, Iran Khodro, etc. - as well as for garage door openers.
After the confidential specifications have been leaked on a Russian website (Code Hopping Decoder using a PIC16C56) in 2006, several cryptanalysts have found substantial weaknesses in the design of the algorithm and the hardware on which it is implemented (Robert R. Enderlein, S Vaudenay, P Sepehrdad. KeeLoq. EPFL, Semester Project 2010.).
Please note this algorithm is pretty weak and should not be used for any real crypto.
KeeLoq is a block cipher with a 64-bit key and a 32-bit block size. The cipher operates on two registers for 528 clock cycles to produce the ciphertext, based on the following shape:
KeeLoq decryption algorithm operates on two registers for 528 rounds, to produce the plaintext for a given key and ciphertext, according to the following shape.
| key | plaintext | ciphertext |
|---|---|---|
0xbeefdeadbeefdead |
0x2000c022 |
0x054c90c2 |
0x5cec6701b79fd949 |
0xf741e2db |
0xe44f4cdf |
0x5cec6701b79fd949 |
0x0ca69b92 |
0xa6ac0ea2 |