PyQuorum is a cryptographic library for secret sharing and key management. Prior to 0.2.1, the mul_mod function implements multiplication via a binary expansion loop whose execution time depends on the Hamming weight of the second operand (the exponent). An attacker who can measure the time of secret‑sharing operations (e.g., via a remote service) could progressively recover the values of shares, ultimately leading to secret reconstruction. This vulnerability is fixed in 0.2.1.

Affected: PyPI: pyquorum

### Impact The `mul_mod` function implements multiplication via a binary expansion loop whose execution time depends on the Hamming weight of the second operand (the exponent). An attacker who can measure the time of secret‑sharing operations (e.g., via a remote service) could progressively recover the values of shares, ultimately leading to secret reconstruction.

### Patches https://github.com/svvqt/pyquorum/releases/tag/v0.2.1

Affected: PyPI: pyquorum

### Impact The `mul_mod` function implements multiplication via a binary expansion loop whose execution time depends on the Hamming weight of the second operand (the exponent). An attacker who can measure the time of secret‑sharing operations (e.g., via a remote service) could progressively recover the values of shares, ultimately leading to secret reconstruction.

### Patches https://github.com/svvqt/pyquorum/releases/tag/v0.2.1