Author: Pulat Yunusov 2017-12-11 22:23:21
Published on: 2017-12-11T22:23:21+00:00
Peter Todd, a Bitcoin developer, proposed a system of secure token transfers using single-use-seals. The system is based on the closing of a unique object or seal over a message only once to prevent double-spends. Single-use-seals are generated by a trusted notary, with each seal committing to that notary's identity, and witnesses being cryptographic signatures produced by that notary. The system can be used for both indivisible and divisible asset transfers.In the case of divisible assets, a spend commitment is made to a set of outputs, and a split commitment is made to a set of zero or seal/value tuples, with the sum value of the split being the sum of a values in the split. The recipient can verify the secure transfer of an asset by generating a fresh seal, asking the sender to create a new split output for that seal and requested output amount, and verifying that the newly created split output is valid. To achieve scalability, a proof-of-publication ledger can be used, where consensus over the state of the ledger is achieved with a second single-use-seal implementation.The context discusses the size of data required to prove ownership status of a token in a trustless manner. It explains that the merkle path down k/v tree, consisting of 32 levels with 32 bytes per level, along with key/value consisting of 32 bytes predicate hash and 1KB script sig, amounts to approximately 3KB per ledger. The update rate is estimated at 356 days per year with 12 updates per day, resulting in 13MB of data per year.However, these are worst case numbers and can be reduced by only publishing valid signatures or assuming no constant attacks. Additionally, for clients with multiple tokens, much of the data can be shared amongst each token. With optimizations, the marginal cost per token after the first one is just 1KB/ledger update, or 4.4MB/year. This is an excellent result for many use cases.
Updated on: 2023-06-12T22:37:23.794511+00:00