Knowledge Base

Overview

A 2020 blog post by Ittai Abraham on the Decentralized Thoughts blog that revisits the 1991 digital timestamping work of Stuart Haber and W. Scott Stornetta and argues it constitutes “the first blockchain.” The article explains how their hash-chaining scheme created an immutable, ordered record of documents years before Bitcoin, and traces the direct lineage from that construction to Nakamoto’s design. It presents the scheme’s components, its security guarantees, its centralized trust assumptions, and how Bitcoin replaced those assumptions with decentralized consensus.

Key points

• The Haber-Stornetta timestamping scheme (1991) links successive time-stamp certificates into a hash chain, so each certificate cryptographically depends on the previous one, producing a tamper-evident ordered log.
• The system has three parts: users who submit certification requests, a Time-Stamp Service (TSS) that batches requests into a Merkle tree and chains each interval hash to the prior interval hash, and a public repository that durably publishes the interval hashes (famously exemplified by publication in a newspaper such as the New York Times).
• Users receive a Merkle inclusion proof binding their document to a published interval hash, enabling later verification without trusting the document itself.
• Claimed security properties: forward-dating is infeasible because future requests are unknown, backdating is infeasible because it would require reforging the subsequent certificate chain (relying on collision-resistant hashing), and the only feasible attack is fabricating an entire alternate chain longer than expected.
• Bitcoin adapted this design, replacing the trusted, non-censoring TSS and durable repository with miners and Nakamoto Consensus (proof-of-work), so decentralized incentives provide ordering and immutability instead of centralized trust.
• The article notes related and derived uses of hash chaining and public logs, including Git commit history, Certificate Transparency, and IPFS, and predicts verifiable timestamping will become broadly useful across legal, credentialing, and news domains.

Relevance to Truestamp

Truestamp’s architecture descends directly from the Haber-Stornetta model described here: it batches submitted items into an Merkle tree, issues inclusion proofs, and establishes a submission window rather than a claimed creation time. Where the original scheme published interval hashes in a newspaper for durability, Truestamp performs public blockchain commitment to Stellar and Bitcoin to make its block hashes externally verifiable.

Citations

1. The First Blockchain or How to Time-Stamp a Digital Document. Ittai Abraham, Decentralized Thoughts, July 5, 2020.