Post-Quantum Cryptographic Migration Protocol Specification

Role: Cryptographic Engineering Researcher and Security Architect

Context

• Existing legacy cryptographic baseline: {{legacy_cipher_suite}}
• Standardized PQC literature and algorithms: {{nist_pqc_standards_scope}}
• System performance and latency budget: {{performance_budget_ms}}
• Target security horizon and threat model: {{threat_horizon_years}}
• Target transport and data protocol: {{target_transport_protocol}}
• Runtime host and platform constraints: {{platform_constraints}}

Task

Synthesize post-quantum cryptography research and benchmark literature from {{nist_pqc_standards_scope}} to draft an end-to-end cryptographic migration and implementation specification that transitions {{legacy_cipher_suite}} into quantum-resistant cipher suites within {{target_transport_protocol}}.

Method

1. Review cryptanalytic bounds, side-channel attack literature, and parameter sets in {{nist_pqc_standards_scope}}.
2. Compare key sizes, ciphertext overhead, and signature sizes between {{legacy_cipher_suite}} and candidate PQC algorithms.
3. Compute handshake latency and packet fragmentation impacts within {{target_transport_protocol}} under {{performance_budget_ms}}.
4. Design a hybrid classical/post-quantum KEM and signature scheme to satisfy {{threat_horizon_years}}.
5. Evaluate implementation vulnerability literature, including constant-time validation and fault-injection resistance on {{platform_constraints}}.
6. Formulate wire-level packet structures, key exchange flows, and cipher suite negotiation protocols.
7. Detail certificate chain transformation rules and backward compatibility fallback strategies.
8. Define security assurance verification test vectors and side-channel leakage benchmarking criteria.

Constraints

• MUST adhere to formal algorithm specifications defined in {{nist_pqc_standards_scope}}.
• MUST NOT specify purely post-quantum primitives where hybrid classical-quantum modes are required for compliance during migration.
• Handshake expansion MUST NOT cause unhandled MTU fragmentation within {{target_transport_protocol}}.
• All primitive recommendations must explicitly quantify impact against {{performance_budget_ms}}.

Output format

Provide a technical cryptographic specification containing:

1. Cryptographic Literature & Parameter Synthesis (Markdown table of 3-4 PQC algorithms comparing public key size, ciphertext size, keygen CPU cycles, and encap/decap timings)
2. Hybrid Protocol Specification (state diagrams, handshake message sequence, wire formats)
3. Cipher Suite Selection Matrix (explicit algorithm identifiers, OIDs, and curve pairings)
4. Hardware & Platform Implementation Guidance for {{platform_constraints}} (vector extensions, memory alignments, constant-time guarantees)
5. Cryptographic Validation & Test Vector Protocol

Self-review

• Confirm that combined public key and ciphertext sizes do not exceed protocol buffer limits in {{target_transport_protocol}}.
• Verify that side-channel vulnerability mitigation literature has been addressed for {{platform_constraints}}.
• Ensure hybrid key derivation functions conform to standard cryptographic combiners.