Reasoning about the future in blockchain databases

Sara Cohen, Adam Rosenthal, Aviv Zohar

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

5 Scopus citations


A key difference between using blockchains to store data and centrally controlled databases is that transactions are accepted to a blockchain via a consensus mechanism, and not by a controlling central party. Hence, once a user has issued a transaction, she cannot be certain if it will be accepted. Moreover, a yet unaccepted transaction cannot be retracted by the user, and may (or may not) be appended to the blockchain at any point in the future. This causes difficulties as the user may wish to formulate new transactions based on the knowledge of which previous transactions will be accepted. Yet this knowledge is inherently uncertain.We introduce a formal abstraction for blockchains as a data storage layer that underlies a database. The main issue that we tackle is the need to reason about possible worlds, due to the uncertainty in transaction appending. In particular, we consider the theoretical complexity of determining whether it is possible for a denial constraint to be contradicted, given the current state of the blockchain, pending transactions, and integrity constraints on blockchain data. We then present practical algorithms for this problem that work well in practice.

Original languageAmerican English
Title of host publicationProceedings - 2020 IEEE 36th International Conference on Data Engineering, ICDE 2020
PublisherIEEE Computer Society
Number of pages4
ISBN (Electronic)9781728129037
StatePublished - Apr 2020
Event36th IEEE International Conference on Data Engineering, ICDE 2020 - Dallas, United States
Duration: 20 Apr 202024 Apr 2020

Publication series

NameProceedings - International Conference on Data Engineering
ISSN (Print)1084-4627


Conference36th IEEE International Conference on Data Engineering, ICDE 2020
Country/TerritoryUnited States

Bibliographical note

Publisher Copyright:
© 2020 IEEE.


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