Analysis and improvement for forward security digital signature schemes based on n-th root module m
Bohan Li · Journal of Communications · 2010
Forward security plays an important role in reducing the loss that aroused for the reason of secret keys exposure effectively,which has been becoming a hotspot in the researches of cryptography.It’s found that these existing schemes have security omission and are lack of forward security through the detailed security analysis of forward-secure digital signature schemes based on n-th root module m hard problem.It’s necessary to explain the essential reason that an adversary succeeded in forging the valid signatures based on the class of forward-secure digital signature schemes through the security analysis.In addition,according to the hard problem of digital signature scheme in the finite field,one of the signature schemes was improved by using the information about the current secret key to sign the message.The analysis of security and efficiency shows that the improved scheme has the features of forward-secure and resisting forging attack,as well as higher signing speed.The proposed method is equally applicable to such other digital signature schemes based on n-th root module m hard problem.Moreover,this improved method has guiding significance and prac-tical application values to further optimal design of some special signature schemes such as forward-secure proxy signature scheme,forward-secure group signature scheme,and forward-secure multi-signature scheme etc.