Consensys has integrated the Divide-and-Pair algorithm for accelerating elliptic-curve security checks into its open-source cryptography library, gnark-crypto. According to Foresight News, Consensys said its cryptographer Youssef El Housni collaborated with researchers from Wuhan University of Technology, KU Leuven’s COSIC lab, and the National Academy of Sciences of Belarus on a paper proposing the method.
The algorithm accelerates subgroup membership testing, a check used to guard against small-subgroup attacks and required for non-prime-order curves such as Curve25519, though it can slow computations. Divide-and-Pair was reported to be no slower than two leading existing methods across different curves, with speedups of about 1.6 times on Curve25519, 1.3 times on Curve448, 1.4 times on GC256A, 10.8 times on FourQ, and seven times on Jubjub.
The gnark-crypto library is used by Besu, Linea, Geth, and systems based on gnark, including Succinct and Lighter. The paper was accepted by the IACR Transactions on Cryptographic Hardware and Embedded Systems (TCHES) and is scheduled to be presented at CHES 2027.