NLM-128, an Improved LM-Type Summation Generator with 2-Bit memories
Hoon Jae Lee, SangMin Sung, HyeongRag Kim · 2009
The NLM family of key stream generator is based on the LM-type summation generator. A nonlinear feedback shift register is added to the LM-type summation generator to provide a security enhancement. NLM-128, a specific cipher from the NLM family, is proposed. It takes a 128-bit key and a 128-bit initialization vector, has 258 bits of internal state, and achieves a security level of 128 bits. In this paper, we present the security analysis of NLM-128, including the resistance to known attacks against the summation generator and LM generator.