Crypto-Current (062)

§5.861 — The early 1990s saw the conceptual innovation of robust (or ‘append-only’) data-structures capable of providing secure ledgers. Such structures introduce a gradient. They make data-bases sedimentary, and time-like.[1] The past is protected against revision, as a type of artificial, hard or ideal memory. Irrevocable commitments were thus digitally supportable. Since backing out of an executed deal is the typical mode of double-spending, a capability for the hardening of commitments has special relevance to the implementation of cryptocurrency. Indeed, its importance is such that there is a tendency among much Bitcoin commentary to reduce the innovation to ‘the blockchain’ which is itself then summarized as a distributed, revision-resistant ledger. Remaining within the Narayanan and Clark schema, the technological lineages leading to the emergence of such decentralized chronotypic databases are themselves susceptible to further triadic classification. Specifically, they assemble advances in the fields of linked time-stamping, Merkle trees, and byzantine fault tolerance.


[1] Narayanan and Clark capture the philosophical essentials well. “In a simplified version of Haber and Stornetta’s proposal, documents are constantly being created and broadcast. The creator of each document asserts a time of creation and signs the document, its timestamp, and the previously broadcast document. This previous document has signed its own predecessor, so the documents form a long chain with pointers backwards in time. An outside user cannot alter a timestamped message since it is signed by the creator, and the creator cannot alter the message without also altering the entire chain of messages that follows. Thus, if you are given a single item in the chain by a trusted source (e.g., another user or a specialized timestamping service), the entire chain up to that point is locked in, immutable, and temporally ordered.”

https://queue.acm.org/detail.cfm?id=3136559