Proofs of Work and Bread Pudding Protocols(Extended Abstract) [chapter]

Markus Jakobsson, Ari Juels
1999 Secure Information Networks  
We formalize the notion of a proof of work (POW). In many cryptographie protocols, a prover seeks to convince a verifier that she possesses knowledge of a secret or that a certain mathematical relation holds true. By contrast, in a POW, a prover demonstrates to a verifier that she has performed a certain amount of computational work in a specified interval of time. POWs have served as the basis of a number of security protocols in the literat ure, but have hitherto lacked careful
more » ... n. In this paper, we offer definitions treating the notion of a POW and related concepts. We also introduce the dependent idea of a bread pudding protocol. Bread pudding is a dish that originated with the purpose of reusing bread that has gone stale. In the same spirit, we define a bread pudding protocol to be a POW such that the computational effort invested in the proof may be reused by the verifier to achieve aseparate, useful, and verifiably correct computation. As an example of a bread pudding protocol, we show how the MicroMint scheme of Rivest and Shamir can be broken up into a collection of POW s. These POW s can not only serve in their own right as mechanisms for security protocols, but can also be harvested in order to outsource the MicroMint minting operation to a large group of untrusted computational devices. B. Preneel (ed.), Secure Information Networks
doi:10.1007/978-0-387-35568-9_18 fatcat:7h24a7dje5dszl57xxjjzhzhue