2016/08/23 by Thanh Bui, Bui, Thanh, Tuomas Aura +1
Computer Science · Social Sciences · #Blockchain Technology Applications and Security #Cryptography and Data Security #Access Control and Trust
paper · pdf · doi:10.48550/arxiv.1608.06592
There has recently been a flood of interest in potential new applications of\nblockchains, as well as proposals for more generic designs called public\nledgers. Most of the novel proposals have been in the financial sector.\nHowever, the public ledger is an abstraction that solves several of the\nfundamental problems in the design of secure distributed systems: global time\nin the form of a strict linear order of past events, globally consistent and\nimmutable view of the history, and enforcement of some application-specific\nsafety properties. This paper investigates the applications of public ledgers\nto access control and, more specifically, to group management in distributed\nsystems where entities are represented by their public keys and authorization\nis encoded into signed certificates. It is particularly difficult to handle\nnegative information, such as revocation of certificates or group membership,\nin the distributed setting. The linear order of events and global consistency\nsimplify these problems, but the enforcement of internal constraints in the\nledger implementation often presents problems. We show that different types of\nrevocation require slightly different properties from the ledger. We compare\nthe requirements with Bitcoin, the best known blockchain, and describe an\nefficient ledger design for membership revocation that combines ideas from\nblockchains and from web-PKI monitoring. While we use certificate-based\ngroup-membership management as the case study, the same ideas can be applied\nmore widely to rights revocation in distributed systems.\n