Kim Dong-Chan, Jeon Chang-Yeol, Kim Minji, Park Dong Hyun, Kim Dong Hyeon, Kim Yeonghyo

Future cryptography Design Lab., Kookmin University

(last updated: 2024.10.21.)

About PALOMA

We propose PALOMA, a new code-based KEM(Key Encapsulation Mechanism), which has the following features:

• Trapdoor based on SDP(Syndrome Decoding Problem) with a binary separable (not irreducible) Goppa code.
• IND-CCA2-secure KEM based on FO(Fujisaki-Okamoto) transformation.

Parameter sets

PALOMA provides three parameter sets: PALOMA-128, PALOMA-192, and PALOMA-256, corresponding to security strength levels of 128-bit, 192-bit, and 256-bit, respectively.

Each parameter set was carefully chosen to meet the following conditions, ensuring efficient implementation.

1. Binary separable Goppa codes are defined in $F_{2^{13}}$ which can be used for PALOMA-128, PALOMA-192, and PALOMA-256 simultaneously,
2. $n + t \leq 2^{13}$ to define a support set and a Goppa polynomial,
3. $n \equiv k \equiv t \equiv 0 \pmod {64}$ for 64-bit word-aligned implementation, and
4. $k/n > 0.7$ to reduce the size of a public key, and
5. Enough security margin.

Performance

Data size (in bytes)