Peakhour.IO - JA3

Public Fingerprint Databases Are Not Ground Truth

AC — Sun, 30 Aug 2026 09:00:00 +1000

We reviewed the main public fingerprint resources. The formats are open, but current application labels and auditable ground truth remain scarce.

A Network Fingerprint Is a Cohort, Not a Client

AC — Sun, 09 Aug 2026 09:00:00 +1000

TLS fingerprints group similar protocol implementations. They do not prove which application, device or person made a request.

Two Lineages of TLS Fingerprinting: JA3, JA4 and Cisco Mercury

AC — Sun, 26 Jul 2026 09:00:00 +1000

JA4 did not descend from Cisco Mercury. The two projects come from different strands of TLS fingerprinting research and solve different operational problems.

Before JA3: How TLS Handshakes Became Fingerprints

AC — Sun, 19 Jul 2026 09:00:00 +1000

JA3 made TLS fingerprints easy to log and share, but the technical ideas behind it had already been tested in SSL Labs experiments, a p0f patch and FingerprinTLS.

One ClientHello, Three Fingerprints: JA3, JA4 and Mercury

AC — Sun, 12 Jul 2026 09:00:00 +1000

A reproducible lab runs JA3, JA4 and Cisco Mercury against the same TLS ClientHello and compares what each fingerprint preserves.