tls-pq-bench/docs/measurement-methodology.md

Measurement methodology

Definitions

Handshake latency

Time from sending ClientHello until the TLS session is ready to exchange application data (handshake completed).

Operationally:

• measured at application level (recommended) using timestamps around the TLS connection establishment, OR
• measured via packet capture (tcpdump) by correlating handshake messages.

TTLB (Time-to-Last-Byte)

Time from starting the request until the last byte of the response body is received by the client.

Operationally:

• measured in the client application by timestamping:
  • T0: immediately before connect / first write attempt
  • T_end: after reading the full response payload

Measurement principles

• Prefer monotonic clocks (e.g., std::time::Instant)
• Run many iterations; report distribution (p50/p95/p99) not only mean
• Separate:
  • cold handshakes (no resumption)
  • optional: resumed handshakes (if you choose to include later)

What to record per run

• key exchange mode: x25519 | x25519mlkem768
• payload size (bytes)
• concurrency level
• number of iterations
• warmup iterations
• CPU pinning info (if used)
• system info (kernel, CPU, governor)
• network profile (baseline / netem parameters)

Output format

Write newline-delimited JSON (NDJSON) for easy aggregation:

Example record:

{
    "mode": "x25519",
    "payload_bytes": 1024,
    "concurrency": 1,
    "iter": 42,
    "handshake_ms": 8.3,
    "ttlb_ms": 12.1
}