Official service · Central Bank of LiberiaOperated under the Public Procurement & Concessions Act 2010
Sentinel
CBL Procurement Portal
The Sentinel substrate · open transparency

Every procurement event, recorded, hash-linked, and anchored.

Sentinel's audit substrate is a tamper-evident chain. Each tender publication, bid submission, evaluation score, award decision, and contract amendment emits a hash-linked event. The chain is anchored hourly to a public timestamp authority and witnessed by the PPCC regulator. You can verify the chain end-to-end with no special access.

Chain entries · all time
184,419
External anchors
8,742
Last verified
14:08 UTC
Verification mismatches · all time
0
Independent verification

Verify any chain entry yourself

Provide a chain sequence number or a hash. The verifier walks the chain from your entry back to the last anchored block, reproduces the linkage, and confirms (or denies) tamper-evidence end-to-end. No login required.

Entry · sequence number or hash
Example: #184,392 · or paste a 64-character hash · case-insensitive
Anchor log · hourly

External witnesses

Each hour, the head of the Sentinel chain is anchored to the Bitcoin blockchain via OpenTimestamps and cross-witnessed by the PPCC e-GP portal. Two independent authorities, neither under CBL's control, maintain the timeline.

  1. 2026-05-21 14:00 UTCOpenTimestamps · BTC main#184,201 → #184,392
    891,242tx
  2. 2026-05-21 13:00 UTCOpenTimestamps · BTC main#184,008 → #184,201
    891,236tx
  3. 2026-05-21 12:00 UTCOpenTimestamps · BTC main#183,889 → #184,008
    891,229tx
  4. 2026-05-21 11:00 UTCOpenTimestamps · BTC main#183,720 → #183,889
    891,222tx
  5. 2026-05-21 10:00 UTCPPCC witness anchor#183,540 → #183,720
    ppcc-anchor-2614tx