Cryptology ePrint Archive: Report 2018/425

Implementing RLWE-based Schemes Using an RSA Co-Processor

Martin R. Albrecht and Christian Hanser and Andrea Hoeller and Thomas Pöppelmann and Fernando Virdia and Andreas Wallner

Abstract: We repurpose existing RSA/ECC co-processors for (ideal) lattice-based cryptography by exploiting the availability of fast long integer multiplication. Such co-processors are deployed in smart cards in passports and identity cards, secured microcontrollers and hardware security modules (HSM). In particular, we demonstrate an implementation of a variant of the Module-LWE-based Kyber Key Encapsulation Mechanism (KEM) that is tailored for high performance on a commercially available smart card chip (SLE 78). To benefit from the RSA/ECC co-processor we use Kronecker substitution in combination with schoolbook and Karatsuba polynomial multiplication. Moreover, we speed-up symmetric operations in our Kyber variant using the AES co-processor to implement a PRNG and a SHA-256 co-processor to realise hash functions. This allows us to execute CCA-secure Kyber768 key generation in 79.6 ms, encapsulation in 102.4 ms and decapsulation in 132.7 ms.

Category / Keywords: learning with errors, smart card, implementation

Original Publication (with minor differences): IACR-CHES-2019

Date: received 9 May 2018, last revised 16 Oct 2018

Contact author: thomas poeppelmann at infineon com

Available format(s): PDF | BibTeX Citation

Version: 20181016:132144 (All versions of this report)

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