This library contains an implementation of FastSQISignHD (Fast Version of the Short Quaternion Isogeny Signature in Higher Dimension), as described in the SQISignHD paper [1]. This library contains two independent sublibraries:

• Signature: a C implementation of the signature based on the SQISign implementation https://github.com/SQISign/the-sqisign.
• Verification-sage: an experimental sagemath implementation of dimension 4 2ドル$-isogeny chains in the Theta model of level 2ドル$ applied to the verification of SQISignHD.

For any further information on those libraries and how to run them, one may refer to the README.md files of each sublibrary.

SQIsignHD is licensed under Apache-2.0. See LICENSE and NOTICE. Third party code is used in each sublibrary. Credits for third party code are given in the License section of the README.md files of each sublibrary.

[1] P. Dartois, A. Leroux, D. Robert, and B. Wesolowski. SQIsignHD: New Dimensions in Cryptography. Cryptology ePrint Archive, Paper 2023/436. 2023. url: https://eprint.iacr.org/2023/436.