Module ct_audit 

Constant-time operation auditing and verification.

This module provides utilities for detecting timing variations in cryptographic operations to help identify potential timing side-channels.

Features

• Timing measurement: High-resolution timing for individual operations
• Statistical analysis: Detect non-constant-time behavior via statistical tests
• Benchmarking: Compare timing across different inputs
• Leak detection: Identify potential timing leaks in cryptographic code

Example

use chie_crypto::ct_audit::{CtAuditor, OperationBenchmark};

// Create an auditor
let auditor = CtAuditor::new("constant_time_eq", 1000);

// Measure an operation multiple times
let mut bench = OperationBenchmark::new("comparison", 1000);
for _ in 0..1000 {
    bench.measure(|| {
        // Your constant-time operation here
        let a = [1u8; 32];
        let b = [1u8; 32];
        let _ = a == b;
    });
}

// Analyze results
let stats = bench.statistics().unwrap();
println!("Mean: {}ns, StdDev: {}ns", stats.mean_ns, stats.std_dev_ns);

Warning

Timing measurements can be affected by:

• CPU frequency scaling
• OS scheduler
• Cache effects
• Branch prediction

Always run audits on a quiet system and interpret results carefully.

Structs

CtAuditor

Auditor for constant-time operations

OperationBenchmark

Benchmark for measuring operation timing

TimingStatistics

Statistical summary of timing measurements

Enums

CtAuditError

Constant-time audit errors

Functions

measure_average

Quick helper to measure average timing over N runs

measure_once

Quick helper to measure operation timing

Type Aliases

CtAuditResult

Result type for constant-time audit operations