Title
Tighter Security Proofs for GPV-IBE in the Quantum Random Oracle Model.
Abstract
In (STOC, 2008), Gentry, Peikert, and Vaikuntanathan proposed the first identity-based encryption (GPV-IBE) scheme based on a post-quantum assumption, namely, the learning with errors (LWE) assumption. Since their proof was only made in the random oracle model (ROM) instead of the quantum random oracle model (QROM), it remained unclear whether the scheme was truly post-quantum or not. In (CRYPTO, 2012), Zhandry developed new techniques to be used in the QROM and proved security of GPV-IBE in the QROM, hence answering in the affirmative that GPV-IBE is indeed post-quantum. However, since the general technique developed by Zhandry incurred a large reduction loss, there was a wide gap between the concrete efficiency and security level provided by GPV-IBE in the ROM and QROM. Furthermore, regardless of being in the ROM or QROM, GPV-IBE is not known to have a tight reduction in the multi-challenge setting. Considering that in the real-world an adversary can obtain many ciphertexts, it is desirable to have a security proof that does not degrade with the number of challenge ciphertext.
Year
DOI
Venue
2018
10.1007/978-3-030-03329-3_9
IACR Cryptology ePrint Archive
DocType
Volume
Citations 
Conference
2018
1
PageRank 
References 
Authors
0.36
33
3
Name
Order
Citations
PageRank
Shuichi Katsumata187.88
Shota Yamada29418.10
Takashi Yamakawa3129.35