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Content Timestamping

CIP: 0002
Title: Content Timestamping
Authos: TP
Status: Stable
Created: 2017-11-09
License: BSD-2-Clause


Content Timestamping is used to record a digital fingerprint of a document on decentralized and tamper-proof blockchain. The timestamp serves as a secure proof of the time at which that document existed. It also secures the integrity of the timestamped data without publicly revealing the content itself. Additionaly publisher of a timespamping transaction can prove control over the address that signed the transaction. This document speciefies an open timestamping stream named timestamp that can be used to publish document or file hashes as proof of existence.


The timestamp-stream is readable and writable by every blockchain participant. The timestamp key must be published as a hex encoded sha256 hash of the data to be timestamped. The data_hex value is optional.

If data_hex is included it must be a UBJSON-encoded data-mapping. Currently the only officially recognized key in that datamapping is comment which can be any comment about the timestamped document like document name, version or reason for timestamping. The maximum processed length of comment is 280 characters.