A Key Encapsulation Mechanism from Low Density Lattice Codes

Key Encapsulation Mechanisms (KEMs) are a set of cryptographic techniques that are designed to provide symmetric encryption key using asymmetric mechanism (public key). In the current study, we concentrate on design and analysis of key encapsulation mechanism from low density lattice codes (KEM-LDLC) to go down the key size by keeping an acceptable level of security. The security of the proposed KEM-LDLC relies on the difficulty of solving the closest vector problem (CVP) and the shortest basis problem (SBP) of the lattices. Furthermore, this paper discusses other performance analyses results such as key size, error performance, and computational complexity, as well as conventional security analysis against applied attacks. Reducing the key size is performed by two approaches: (i) saving the generation sequence of the latin square LDLCs parity-check matrix of as a part of the secret key set; (ii) using the hermite normal form (HNF) of the latin square LDLCs generator matrix as part of the public key set. These enhancements enable us to attain greater efficiency and security compared to earlier code-based KEMs.