Details

Autor(en) / Beteiligte

• Greuet, Aurélien
• Montoya, Simon
• Renault, Guénaël

Titel

On Using RSA/ECC Coprocessor for Ideal Lattice-Based Key Exchange

Ist Teil von

• Constructive Side-Channel Analysis and Secure Design, p.205-227

Ort / Verlag

Cham: Springer International Publishing

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Polynomial multiplication is one of the most costly operations of ideal lattice-based cryptosystems. In this work, we study its optimizations when one of the operands has coefficients close to 0. We focus on this structure since it is at the core of lattice-based Key Encapsulation Mechanisms submitted to the NIST call for post-quantum cryptography. In particular, we propose optimization of this operation for embedded devices by using a RSA/ECC coprocessor that provides efficient and secure large-integer arithmetic. In this context, we compare Kronecker Substitution, already studied in [AHH+19], with two specific algorithms that we introduce: KSV, a variant of this substitution, and an adaptation of the schoolbook multiplication, denoted Shift&Add. All these algorithms rely on the transformation of polynomial multiplication to large-integer arithmetic. Then, thanks to these algorithms, existing secure coprocessors dedicated to large-integer can be re-purposed in order to speed-up post-quantum schemes. The efficiency of these algorithms depends on the component specifications and the cryptosystem parameters set. Thus, we establish a methodology to determine which algorithm to use, for a given component, by only implementing basic large-integer operations. Moreover, the three algorithms are assessed on a chip ensuring that the theoretical methodology matches with practical results.