This repository contains a implementation of HMAC-SHA256 in Circom.
HMAC (Hash-based Message Authentication Code) is a specific type of message authentication code (MAC) involving a cryptographic hash function and a secret cryptographic key. It may be used to simultaneously verify both the data integrity and authenticity of a message.
For more detailed information, refer to:
The circuits in this repository implement HMAC-SHA256. The implementation strictly follows the HMAC standard as described in RFC 2104, using SHA-256 as the hash function. The circuit is designed to be generic and supports:
- Variable message length
- Key size of 256 bits (can be adapted for other sizes)
Check the HmacSha256
| Test Vector | Constraints | Message Length (n) | Key Length (k) | Execution Time (s) |
|---|---|---|---|---|
| 1 | 161,640 | 8 | 20 | 10.249 |
| 2 | 161,676 | 28 | 4 | 10.175 |
| 3 | 162,018 | 50 | 20 | 10.285 |
| 4 | 162,063 | 50 | 25 | 10.755 |
| 5 | 161,748 | 20 | 20 | 10.016 |
| 6 | 225,581 | 54 | 131 | 14.216 |
| 7 | 288,991 | 152 | 131 | 17.882 |
These tests were performed on a Mac Pro with M1 chip and 8GB RAM. The test vectors are based on RFC 4231, which provides standard test cases for HMAC-SHA256.
To run these tests, use the following command:
yarn test