TY - GEN
T1 - Compressed Verification for Post-quantum Signatures with Long-Term Public Keys
AU - Banegas, Gustavo
AU - Le Dévéhat, Anaëlle
AU - Smith, Benjamin
N1 - Publisher Copyright:
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2026.
PY - 2026/1/1
Y1 - 2026/1/1
N2 - Many signature applications—such as root certificates, secure software updates, and authentication protocols—involve long-lived public keys that are transferred or installed once and then used for many verifications. This key longevity makes post-quantum signature schemes with conservative assumptions (e.g., structure-free lattices) attractive for long-term security. But many such schemes, especially those with short signatures, suffer from extremely large public keys. Even in scenarios where bandwidth is not a major concern, large keys increase storage costs and slow down verification. We address this with a method to replace large public keys in GPV-style signatures with smaller, private verification keys. This significantly reduces verifier storage and runtime while preserving security. Applied to the conservative, short-signature schemes Wave and Squirrels, our method compresses Squirrels-I keys from 665 kB to 20.7 kB and Wave822 keys from 3.5 MB to 207.97 kB.
AB - Many signature applications—such as root certificates, secure software updates, and authentication protocols—involve long-lived public keys that are transferred or installed once and then used for many verifications. This key longevity makes post-quantum signature schemes with conservative assumptions (e.g., structure-free lattices) attractive for long-term security. But many such schemes, especially those with short signatures, suffer from extremely large public keys. Even in scenarios where bandwidth is not a major concern, large keys increase storage costs and slow down verification. We address this with a method to replace large public keys in GPV-style signatures with smaller, private verification keys. This significantly reduces verifier storage and runtime while preserving security. Applied to the conservative, short-signature schemes Wave and Squirrels, our method compresses Squirrels-I keys from 665 kB to 20.7 kB and Wave822 keys from 3.5 MB to 207.97 kB.
KW - Code-based cryptography
KW - Compressed GPV
KW - Digital Signatures
KW - Lattice-based cryptography
KW - Post-quantum cryptography
UR - https://www.scopus.com/pages/publications/105023285619
U2 - 10.1007/978-981-95-4434-9_1
DO - 10.1007/978-981-95-4434-9_1
M3 - Conference contribution
AN - SCOPUS:105023285619
SN - 9789819544332
T3 - Lecture Notes in Computer Science
SP - 3
EP - 26
BT - Cryptology and Network Security - 24th International Conference, CANS 2025, Proceedings
A2 - Kim, Yongdae
A2 - Miyaji, Atsuko
A2 - Tibouchi, Mehdi
PB - Springer Science and Business Media Deutschland GmbH
T2 - 24th International Conference on Cryptology and Network Security, CANS 2025
Y2 - 17 November 2025 through 20 November 2025
ER -