This talk introduces a novel IND-CCA2 Key EncapsulationMechanism
(KEM) based on the weighted subset sum problem. The cryptosystem uses a
decoding algorithm inspired by Goppa codes, adapted for the ring of
integers. Decryption is efficiently handled through a truncated version
of the extended Euclidean algorithm. By allowin non-binary alphabets,
the design aims to mitigate traditional lattice-reduction attacks that
have historically compromised knapsack schemes.
Additionally, to protect the system against lattice-reduction attacks
to the private key, two possible masking mechanisms of the public key
are proposed. Since the system is based on basic integer arithmetic, it
offers high computational performance and it is potentially
secure against quantum attacks.