Paper 2023/189
tlock: Practical Timelock Encryption from Threshold BLS
Abstract
We present a practical construction and implementation of timelock encryption, in which a ciphertext is guaranteed to be decryptable only after some specified time has passed. We employ an existing threshold network, the League of Entropy, implementing threshold BLS [BLS01, B03] in the context of Boneh and Franklin's identity-based encryption (IBE) [BF01]. At present this threshold network broadcasts BLS signatures over each round number, equivalent to the current time interval, and as such can be considered a decentralised key holder periodically publishing private keys for the IBE where identities are the round numbers. A noticeable advantage of this scheme is that only the encryptors and decryptors are required to perform any additional cryptographic operations; the threshold network can remain unaware of the TLE and does not have to change to support the scheme. We also release an open-source implementation of our scheme and a live web page that can be used in production now relying on the existing League of Entropy network acting as a distributed public randomness beacon service using threshold BLS signatures.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Preprint.
- Keywords
- timelock encryptiontimelockthreshold cryptographyleague of entropy
- Contact author(s)
-
nikkolasg @ protocol ai
kelseymelissaris @ gmail com
yolan @ protocol ai - History
- 2023-02-15: approved
- 2023-02-13: received
- See all versions
- Short URL
- https://ia.cr/2023/189
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2023/189,
author = {Nicolas Gailly and Kelsey Melissaris and Yolan Romailler},
title = {tlock: Practical Timelock Encryption from Threshold {BLS}},
howpublished = {Cryptology {ePrint} Archive, Paper 2023/189},
year = {2023},
url = {https://eprint.iacr.org/2023/189}
}
