Cryptanalysis of an improved MFE public key cryptosystem
XU Zhao-hu, Xuyun Nie, Hui Wang, Yongjian Liao · International Journal of Security and Networks · 2012
Medium–Field Multivariate (MFE) Public–Key Encryption Scheme which was proposed by Wang et al. was broken by Ding et al. in 2007 through high order linearisation equation attack. In 2009, Tao et al. gave an improvement of MFE. They claimed that the improved MFE is secure against high order linearisation equation attack. However, through theoretical analysis, we find that there are many second order linearisation equations (SOLEs) satisfied by this improved version. Using linearisation equation attack can break this version.