Paper 2020/1019 Original: eprint.iacr.org/2020/1019 ↗
Security of Streaming Encryption in Google's Tink Library
Abstract
We analyze the multi-user security of the streaming encryption in Google's Tink library via an extended version of the framework of nonce-based online authenticated encryption of Hoang et al. (CRYPTO'15) to support random-access decryption. We show that Tink's design choice of using random nonces and a nonce-based key-derivation function indeed improves the concrete security bound. We then give two better alternatives that are more robust against randomness failure. In addition, we show how to efficiently instantiate the key-derivation function via AES, instead of relying on HMAC-SHA256 like the current design in Tink. To accomplish this we give a multi-user analysis of the XOR-of-permutation construction of Bellare, Krovetz, and Rogaway (EUROCRYPT'98).
Metadata
- Available format(s)
PDF- Category
- Secret-key cryptography
- Publication info
- Preprint.
- History
- 2020-08-27: last updated
- 2020-08-27: published
- Short URL
- https://ia.cr/2020/1019
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2020/1019,
author = {Viet Tung Hoang and Yaobin Shen},
title = {Security of Streaming Encryption in Google's Tink Library},
howpublished = {Cryptology {ePrint} Archive, Paper 2020/1019},
year = {2020},
url = {https://eprint.iacr.org/2020/1019}
}