Proof of Life

Verification

Verify card TR-STZV

Every claim below is checked with open, generic tools — a Python interpreter and the ots command — against math and the Bitcoin blockchain. None of it requires this site, or its operator, to still exist.

1. The record

Serial
TR-STZV
Registered at (UTC)
2026-07-14T08:44:54.391Z
Note SHA-256
b4d6ba17e23d014d2ccd7412e9a755fc1712470dff47923cf1970303cc96e58c
Proof phrase
TIGER BUTTON TURTLE
Photo SHA-256
a22215f180a30502aac94862d6d44c10182992c0b7b891c68d6def515c971a93
Photo recorded (UTC)
2026-07-14T08:46:48.055Z

The proof phrase is derived from this record's serial and timestamp with a server-side key — it could not have been known before the registration existed. Compare it against the handwriting on the physical card, or listen for it in a proof photo/video. The photo SHA-256 above and witnesses carry signed-dump trust (Ed25519 + the dump's generated_at), not the Bitcoin anchor below — two different grades, stated plainly.

2. Leaf hash

The leaf hash is a fixed function of the serial, timestamp, and note (or an empty string, if private):

inner = sha256(note or "")
leaf_hash = sha256(serial + registered_at + inner)

5ea9fac7e5e1d5fffdee740e45364da30828e01a06553dde7df229179e2150a2

Recompute it yourself:

python3 -c "
import hashlib
serial = "TR-STZV"
registered_at = "2026-07-14T08:44:54.391Z"
note = "First test of proof of life"
inner = hashlib.sha256(note.encode()).digest()
print(hashlib.sha256(serial.encode() + registered_at.encode() + inner).hexdigest())
"

Output should equal 5ea9fac7e5e1d5fffdee740e45364da30828e01a06553dde7df229179e2150a2.

3. Merkle inclusion

This leaf is included in the Merkle tree whose root is:

5ea9fac7e5e1d5fffdee740e45364da30828e01a06553dde7df229179e2150a2

Inclusion path (leaf → root, 0 steps):

path = [
]

Verify with pure hashlib (no dependency on this server):

python3 -c "
import hashlib
leaf = bytes.fromhex("5ea9fac7e5e1d5fffdee740e45364da30828e01a06553dde7df229179e2150a2")
root = bytes.fromhex("5ea9fac7e5e1d5fffdee740e45364da30828e01a06553dde7df229179e2150a2")
path = []
h = leaf
for step in path:
    sib = bytes.fromhex(step['hash'])
    h = hashlib.sha256(sib + h).digest() if step['side'] == 'left' else hashlib.sha256(h + sib).digest()
print('VALID' if h == root else 'INVALID')
"

4. OpenTimestamps / Bitcoin

Confirmed in a Bitcoin block — independently verifiable.

Install the standard, open-source client and reconstruct the two files it expects:

pip install opentimestamps-client
curl -o root.bin.ots "https://proofoflife.cwandt.com/api/anchor/1/proof.ots"
python3 -c "open('root.bin','wb').write(bytes.fromhex("5ea9fac7e5e1d5fffdee740e45364da30828e01a06553dde7df229179e2150a2"))"
ots verify root.bin.ots -f root.bin

A confirmed anchor prints Success! Bitcoin block <height> attests existence as of <UTC timestamp>.

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