Knowledge Base
Browse the concepts behind Truestamp. Follow the links between concepts, or search across everything.
Tagged: proof-of-existence
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Library
Blockchain-based Infrastructure for Proof of Existence in eGovernment
Vizzarri (2020) CEUR paper proposing a Bitcoin blockchain proof-of-existence scheme for eGovernment documents using OP_RETURN hash records, contrasted with centralized, decentralized, and distributed trusted-third-party systems.
Carbon Dating the Internet Archive with OpenTimestamps
Peter Todd's primary-source account (May 2017) of timestamping about 750 million Internet Archive files with OpenTimestamps: SHA1 digests read from the archive's own metadata, aggregated through a calendar server into a Merkle tree, and committed in a single Bitcoin transaction.
Comprehensive Guide to Merkle Trees, Merkle Proofs, and Merkle Roots
Cyfrin developer primer defining Merkle trees, proofs, and roots, how pair-wise hashing builds a root, how inclusion proofs verify membership, the second preimage attack, and blockchain uses.
How Does OpenTimestamps Work (r/Bitcoin discussion)
A Reddit r/Bitcoin thread explaining how OpenTimestamps proves data existence using SHA-256 hashes, calendar-server Merkle aggregation, .ots proof files, and Bitcoin blockchain commitment.
How The Bitcoin Blockchain Is Fighting Fraud In Guatemala's Presidential Elections
Bitcoin Magazine feature on Simple Proof, which used OpenTimestamps and the Bitcoin blockchain to timestamp Guatemala's 2023 election tally sheets, creating tamper-evident proof-of-existence records citizens could independently verify.
Improving the Efficiency and Reliability of Digital Time-Stamping
Bayer, Haber, and Stornetta 1993 paper introducing hash trees (Merkle trees) to batch digital time-stamp requests, reducing storage and verification cost and enabling time-stamp renewal to extend signature lifetimes.
OpenTimestamps
OpenTimestamps: an open, free standard for Bitcoin-backed proof-of-existence timestamping (client-side hashing, calendar-server Merkle aggregation, .ots proofs), with a feature comparison against Truestamp.
The First Blockchain or How to Time-Stamp a Digital Document
Decentralized Thoughts article by Ittai Abraham on the 1991 Haber-Stornetta digital timestamping scheme: hash chaining, Merkle trees, trusted repositories, and its influence on Bitcoin.
Timestamping with OpenTimestamps, FOSDEM 2024
FOSDEM 2024 slide deck on OpenTimestamps: a decentralized, trust-minimized protocol that proves data existed at a point in time by Merkle-aggregating hashes through calendar servers and committing to the Bitcoin blockchain.
Why and how Bitcoin uses Merkle trees - Applied Mathematics Consulting
John D. Cook blog post explaining how Bitcoin organizes block transactions into a Merkle tree, storing only the root in the block header to enable logarithmic-size Simple Payment Verification proofs.