An implementation of KeeLoq by C programming language. Besides encryption and decryption functions, this implementation contains one function called polynomials, to generate polynomial equations of KeeLoq over finite field GF(2).
KeeLoq is a proprietary block cipher owned by Microchip, 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 [2] in 2006, several cryptanalysts have found substantial weaknesses in the design of the algorithm and the hardware on which it is implemented [1].
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 [1], 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.
git clone https://github.com/hadipourh/KeeLoq
cd KeeLoq
make
Open the terminal within the KeeLoq directory, and then execute the following command:
./main
key | plaintext | ciphertext
0x5cec6701b79fd949 | 0xf741e2db | 0xe44f4cdf
0x5cec6701b79fd949 | 0x0ca69b92 | 0xa6ac0ea2
[1]- Robert R. Enderlein, S Vaudenay, P Sepehrdad. KeeLoq. EPFL, Semester Project 2010.