Preventing Information Leakage from Encoded Data in Lattice Based Cryptography

Lattice based Cryptography is an important sector which is ensuring cloud data security in present world. It provides a stronger belief of security in a way that the average-case of certain problem is akin to the worst-case of those problems. There are strong indications that these problems will remain safe under the availability of quantum computers, unlike the widely used issues like integer-factorization and discrete logarithm upon which most of the typical cryptosystems relies. In this paper, we tend to discuss the security dimension of Lattice based cryptography whose power lies within the hardness of lattice problems. Goldreich-Goldwasser-Halevi (GGH) public-key cryptosystem is an exemplar of lattice-based cryptosystems. Its security depends on the hardness of lattice issues. GGH is easy to understand and is widely used due to its straightforward data encoding and decoding procedures. Phong Nguyen, in his paper showed that there's a significant flaw within the style of the GGH scheme as ciphertext leaks information on the plaintext. Due to this flaw the practical usage of GGH cryptosystem is limiting to some extent. So as to enhance the safety and usefulness of the GGH cryptosystem, in this paper we proposed an improvised GGH encryption and decryption functions which prevented information leakage. We have implemented a package in MATLAB for the improvement of GGH cryptosystem. In our work we proposed some methods to improve GGH algorithm and make it more secure and information leakage resistant.