What is constant-time testing?

Constant-time testing is a security methodology used to verify that the execution time of a cryptographic function does not vary based on the secret data it processes, thereby preventing timing attacks.

How does this skill assist in security audits?

It provides a comprehensive handbook of known vulnerability patterns, tool recommendations (like dudect and Timecop), and a multi-phase workflow to detect and fix timing leaks.

Can this skill help detect cache-timing attacks?

Yes, it specifically identifies secret-dependent array accesses, which are a primary source of cache-timing vulnerabilities in algorithms like AES.

Which programming languages does this skill focus on?

While timing principles apply to all languages, the guidance specifically addresses C/C++ patterns often found in low-level cryptographic libraries and assembly optimizations.

Is statistical testing enough to guarantee security?

No, statistical testing (like dudect) detects differences but cannot prove their absence. This skill recommends combining it with formal verification for high-assurance requirements.

Constant-Time Security Testing

Name: Constant-Time Security Testing
Author: trailofbits

bytrailofbits

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939

安全与测试

Detects and analyzes timing side-channel vulnerabilities in cryptographic code to prevent secret data leakage.

关于

The Constant-Time Testing skill provides specialized guidance for auditing cryptographic implementations to ensure execution time remains independent of secret data. It helps security researchers and developers identify risky patterns such as conditional jumps, cache-sensitive array accesses, and processor-dependent operations that can expose private keys. By leveraging a structured workflow involving statistical tools like dudect and dynamic analysis tools like Timecop, this skill enables users to detect, pinpoint, and remediate timing side channels across various cryptographic primitives and protocols.

主要功能

Guides dynamic runtime tracing to pinpoint exact lines of code causing leaks.
Provides workflows for statistical timing analysis using dudect and Welch's t-test.
Covers formal verification and symbolic execution approaches for high-assurance security.
Identifies common timing violation patterns like conditional branching and cache-timing leaks.
939 GitHub stars
Offers remediation strategies and masking techniques for cryptographic implementation.

使用场景

Auditing cryptographic primitives and protocols for side-channel resistance.
Implementing new cryptographic algorithms from scratch while following constant-time best practices.
Reviewing security-critical pull requests that handle private keys or sensitive tokens.

关于

主要功能

Guides dynamic runtime tracing to pinpoint exact lines of code causing leaks.
Provides workflows for statistical timing analysis using dudect and Welch's t-test.
Covers formal verification and symbolic execution approaches for high-assurance security.
Identifies common timing violation patterns like conditional branching and cache-timing leaks.
939 GitHub stars
Offers remediation strategies and masking techniques for cryptographic implementation.

使用场景

Auditing cryptographic primitives and protocols for side-channel resistance.
Implementing new cryptographic algorithms from scratch while following constant-time best practices.
Reviewing security-critical pull requests that handle private keys or sensitive tokens.