Security analysis of Modified Rivest Scheme
Deepthi Haridas, Sarma Venkataraman, Geeta Varadan · Journal of Mathematical Cryptology · 2014
Abstract The Modified Rivest Scheme (MRS) is an additive homomorphic scheme recently used in many applications which demands third party processing of encrypted data. The present study carries out a comprehensive security analysis of MRS. We work out an attack from the category of known plaintext, chosen plaintext, chosen ciphertext where the adversary is having with him the pair of plaintext and its corresponding ciphertext. It is demonstrated that in such a scenario the adversary can compute the private key of the legitimate node causing threat to the security of the entire system. The novelty of the present study lies in the fact that any attack from the above mentioned category could be mounted on MRS (which is not being attacked so far), irrespective of the fact whether the modulus of the underlying MRS is kept private or made public.