Cryptography, Security, and Privacy-Preserving Computation
Computation Under Adversarial Threats
Security Goals
Cryptography provides confidentiality, integrity, authentication, and non-repudiation; modern security research extends these to secure computation, privacy, and composable guarantees.
Foundational Concepts
What is the main intuition behind zero-knowledge proofs?
Zero-knowledge means convincing without disclosure of the underlying secret.
Correct answer: The verifier is convinced of truth without learning the hidden witness
Why are formal security models important?
Security claims are only meaningful relative to a model of attack.
Correct answer: They precisely define what an adversary can do and what guarantee the scheme provides.
Cryptographic Primitives
Symmetric encryption
- Fast
- Requires shared secret
- Ideal for bulk data
Public-key encryption
- Simpler key distribution
- Typically slower
- Useful for key exchange and identity
Reasoning About a Cryptographic Protocol
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1
Define the adversary and threat model.
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2
State the security goal precisely.
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3
Reduce security to a hardness assumption or simulation argument.
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4
Check composition with other protocol components.
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5
Consider implementation attacks such as side channels.
Which attack class exploits timing, cache behavior, or power usage rather than the cryptographic math itself?
Side-channel attacks exploit implementation leakage.
Correct answer: Side-channel attack
Modern Trend
Privacy-preserving computation increasingly combines cryptography with systems engineering, enabling secure analytics and outsourced computation.
Advanced Frontier
Research-grade topics include post-quantum cryptography, verifiable computation, threshold cryptography, federated learning security, and differential privacy.