Stop fraudsters
your peers
already caught.
Members hash identifiers locally and check them against a synced 4-byte prefix DB. Raw emails and phones never leave your servers — trustdb only sees a 4-byte prefix on probable hits.
Modeled on
Safe Browsing.
A two-step lookup. Common case offline. Rare hits reveal almost nothing.
Hash locally
Your server computes PBKDF2-SHA256 with the network salt — raw identifiers never leave your infrastructure. Try it yourself:
⊥ Runs on Web Crypto — trustdb never sees your input. Only the highlighted 4-byte prefix is ever transmitted, and it collides across many identifiers, so trustdb can't tell which one you checked.
- algorithm
- PBKDF2-SHA256
- salt
- trustdb-network-v1
- iterations
- 100,000
- output
- 256-bit hex
- 02 offline
Check the local prefix DB
Keep a local set of every reported hash truncated to 4 bytes. The common no-match path makes no network call.
prefix = h[:4] if prefix in local_db: - 03 1 request
Confirm with trustdb
On a prefix hit, fetch all full hashes sharing that prefix and compare client-side. trustdb only sees the 4-byte value.
full = trustdb.lookup(prefix) if h in full: - 04 your call
Act on a confirmed match
On a confirmed match, you get the metadata other members reported — severity, category, timestamp — to enforce on.
report = full[h] block(user, report)
Request
access.
trustdb is invite-only. Tell us a little about your team and the surface you're protecting. We reply by email — usually within a few working days.