From Pretty Good To Great: Enhancing PGP using Bitcoin and the Blockchain

摘要

PGP is built upon a Distributed Web of Trust in which the trustworthiness ofa user is established by others who can vouch through a digital signature forthat particular identity. Preventing its wholesale adoption are a number ofinherent weaknesses to include (but not limited to) the following: 1) TrustRelationships are built on a subjective honor system, 2) Only first degreerelationships can be fully trusted, 3) Levels of trust are difficult toquantify with actual values, and 4) Issues with the Web of Trust itself(Certification and Endorsement). Although the security that PGP provides isproven to be reliable, it has largely failed to garner large scale adoption. Inthis paper, we propose several novel contributions to address theaforementioned issues with PGP and associated Web of Trust. To address thesubjectivity of the Web of Trust, we provide a new certificate format based onBitcoin which allows a user to verify a PGP certificate using Bitcoinidentity-verification transactions - forming first degree trust relationshipsthat are tied to actual values (i.e., number of Bitcoins transferred duringtransaction). Secondly, we present the design of a novel Distributed PGP keyserver that leverages the Bitcoin transaction blockchain to store and retrieveBitcoin-Based PGP certificates. Lastly, we provide a web prototype applicationthat demonstrates several of these capabilities in an actual environment.