LEDAkem: a post-quantum key encapsulation mechanism based on QC-LDPC codes
This work addresses the need for secure key exchange in a post-quantum computing era, offering a domain-specific solution with incremental improvements in decoding speed.
The authors tackled the problem of designing a post-quantum key encapsulation mechanism by proposing LEDAkem, based on QC-LDPC codes, which achieves high decoding speeds and compact keypairs, with performance figures provided from an efficient C99 implementation.
This work presents a new code-based key encapsulation mechanism (KEM) called LEDAkem. It is built on the Niederreiter cryptosystem and relies on quasi-cyclic low-density parity-check codes as secret codes, providing high decoding speeds and compact keypairs. LEDAkem uses ephemeral keys to foil known statistical attacks, and takes advantage of a new decoding algorithm that provides faster decoding than the classical bit-flipping decoder commonly adopted in this kind of systems. The main attacks against LEDAkem are investigated, taking into account quantum speedups. Some instances of LEDAkem are designed to achieve different security levels against classical and quantum computers. Some performance figures obtained through an efficient C99 implementation of LEDAkem are provided.