Description
Generating the ECDSA nonce k samples a random number r and then truncates this randomness with a modular reduction mod n where n is the order of the elliptic curve. Meaning k = r mod n. The division used during the reduction estimates a factor q_e by dividing the upper two digits (a digit having e.g. a size of 8 byte) of r by the upper digit of n and then decrements q_e in a loop until it has the correct size. Observing the number of times q_e is decremented through a control-flow revealing side-channel reveals a bias in the most significant bits of k. Depending on the curve this is either a negligible bias or a significant bias large enough to reconstruct k with lattice reduction methods. For SECP160R1, e.g., we find a bias of 15 bits.
INFO
Published Date :
2024-08-27T18:44:52.770Z
Last Modified :
2026-01-27T21:58:42.146Z
Source :
wolfSSL
AFFECTED PRODUCTS
The following products are affected by CVE-2024-1544 vulnerability.
| Vendors | Products |
|---|---|
| Wolfssl |
|
REFERENCES
Here, you will find a curated list of external links that provide in-depth information to CVE-2024-1544.
