The uprise of Bitcoin and other peer-to-peer cryptocurrencies has opened many interesting and challenging problems in cryptography, distributed systems, and databases. The main underlying data structure is blockchain, a scalable fully replicated structure that is shared among all participants and guarantees a consistent view of all user transactions by all participants in the system. In this tutorial, we discuss the basic protocols used in blockchain, and elaborate on its main advantages and limitations. To overcome these limitations, we provide the necessary distributed systems background in managing large scale fully replicated ledgers, using Byzantine Agreement protocols to solve the consensus problem.more »
Blockchains and Databases: Opportunities and Challenges for the Permissioned and the Permissionless
Bitcoin [12] is a successful and interesting example of a global scale peer-to-peer
cryptocurrency that integrates many techniques and protocols from cryptography, distributed systems, and databases. The main underlying data structure is
blockchain, a scalable fully replicated structure that is shared among all participants and guarantees a consistent view of all user transactions by all participants in the system. In a blockchain, nodes agree on their shared states
across a large network of untrusted participants. Although originally devised for
cryptocurrencies, recent systems exploit its many unique features such as transparency, provenance, fault tolerance, and authenticity to support a wide range of
distributed applications. Bitcoin and other cryptocurrencies use permissionless
blockchains. In a permissionless blockchain, the network is public, and anyone
can participate without a specific identity. Many other distributed applications,
such as supply chain management and healthcare, are deployed on permissioned
blockchains consisting of a set of known, identified nodes that still might not
fully trust each other. This paper illustrates some of the main challenges and
opportunities from a database perspective in the many novel and interesting
application domains of blockchains. These opportunities are illustrated using
various examples from recent research in both permissionless and permissioned
blockchains. Two main themes unite the various examples: (1) the important
role of distribution and consensus in managing more »
- Editors:
- Darmont, J; Novikov, B.; Wrembel, R.
- Publication Date:
- NSF-PAR ID:
- 10238788
- Journal Name:
- Advances in Databases and Information Systems
- Page Range or eLocation-ID:
- 3 - 7
- Sponsoring Org:
- National Science Foundation
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