Versions

of On-chain timestamps

Each version of this post is timestamped on Ethereum. The SHA-256 of its source file is the data of a transaction the author sent from their wallet: the block holding the transaction proves the text existed by then, and the transaction's signature proves who sent it.

The post as it reads now is version 1.

Version 1

September 24, 2026, 21:47 UTC

SHA-256: 0a59f99998474f2dddce69633904f6c56da9d88b04180a83160f96f28132f932
Transaction: 0xc5481e2f…787bbf21, block 26,050,093
Sent by: 0x58c2927Ea82f870483879F70D318D447017CbaC8, the author's wallet
Source: v1.mdx

Checking a version

Download the source of a version and hash it, here the latest:

curl -fO https://vincentc.org/posts/on-chain-timestamps/v1.mdx
shasum -a 256 v1.mdx

The result must equal the input data of that version's transaction on Etherscan, and the transaction must come from the address above; where it was sent does not matter. The time shown is the block's. The same record, for programs, is versions.json.