Paper 2021/1693 Original: eprint.iacr.org/2021/1693 ↗

Verifiable Decryption for BGV

Tjerand Silde
Abstract

In this work we present a direct construction for verifiable decryption for the BGV encryption scheme by combining existing zero-knowledge proofs for linear relations and bounded values. This is one of the first constructions of verifiable decryption protocols for lattice-based cryptography, and we give a protocol that is simpler and at least as efficient as the state of the art when amortizing over many ciphertexts. To prove its practicality we provide concrete parameters, resulting in proof size of less than $44 \tau$ KB for $\tau$ ciphertexts with message space $2048$ bits. Furthermore, we provide an open source implementation showing that the amortized cost of the verifiable decryption protocol is only $76$ ms per message when batching over $\tau = 2048$ ciphertexts.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Preprint.
History
2024-06-07: last updated
2021-12-30: published
Short URL
https://ia.cr/2021/1693
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2021/1693,
      author = {Tjerand Silde},
      title = {Verifiable Decryption for BGV},
      howpublished = {Cryptology {ePrint} Archive, Paper 2021/1693},
      year = {2021},
      url = {https://eprint.iacr.org/2021/1693}
}
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