Side Channels

Side channels leak information through indirect signals rather than intended data paths.

Examples

• Timing differences
• Cache behavior
• Memory access patterns
• Error messages
• Query volume
• Output size
• Power or resource usage

Practical Example

A TEE protects plaintext during inference, but timing behavior reveals which branch of a model or retrieval pipeline was used.

PET Implications

TEEs, HE, MPC, and RAG systems need metadata and implementation review, not just high-level architecture diagrams.