UltrafastSecp256k1 v3.3

UltrafastSecp256k1 version 3.3 represents a significant advancement in secp256k1 library performance and security, addressing the needs across various backends including CPU, CUDA, OpenCL, and Metal. This release, encompassing 61 commits, introduces remarkable improvements in batch operations speed—ranging from 17 to 67 times faster than its predecessor, v3.21.1. This leap in performance is primarily attributed to the shift from Jacobian coordinates to an all-affine accumulation strategy for batch scalar multiplications, significantly reducing the computational workload by utilizing mixed Jacobian+Affine additions.

Additionally, this update brings about a 10% increase in OpenCL generator multiplication speed through the introduction of a precomputed affine table, eliminating the need for per-thread table construction. The Schnorr batch verification process has also been optimized with 8 distinct enhancements, such as cached x-only pubkeys and reused scratch buffers, which cumulatively improve efficiency, particularly beneficial for systems like the Lightning Network that verify numerous Schnorr signatures in bulk.

The GPU backends have not been left behind, with CUDA receiving precomputed tweak tables for BIP352 silent payment scanning and Metal being updated to match feature parity with CUDA and OpenCL through several key features. On the security front, UltrafastSecp256k1 v3.3 addresses over 463 code-scanning alerts and completes all planned audit infrastructure items, ensuring robustness against a wide array of potential vulnerabilities.

This release marks a comprehensive update that not only enhances performance across all supported platforms but also significantly bolsters the library's security posture. With these updates, UltrafastSecp256k1 establishes itself as the fastest and most secure implementation of the secp256k1 library available, setting the stage for future developments focused on further GPU acceleration and support for emerging hardware architectures.

For developers and users interested in integrating or upgrading to this latest version, UltrafastSecp256k1 v3.3 is readily accessible across multiple languages and platforms, with detailed instructions provided for each here. This release demonstrates a strong commitment to advancing cryptocurrency infrastructure through open-source collaboration, as evidenced by the project's GitHub repository.