Paper 2023/1693

Elementary Remarks on Some Quadratic Based Identity Based Encryption Schemes

George Teseleanu
Paul Cotan
Abstract

In the design of an identity-based encryption (IBE) scheme, the primary security assumptions center around quadratic residues, bilinear mappings, and lattices. Among these approaches, one of the most intriguing is introduced by Clifford Cocks and is based on quadratic residues. However, this scheme has a significant drawback: a large ciphertext to plaintext ratio. A different approach is taken by Zhao et al., who design an IBE still based on quadratic residues, but with an encryption process reminiscent of the Goldwasser-Micali cryptosystem. In the following pages, we will introduce an elementary method to accelerate Cocks' encryption process and adapt a space-efficient encryption technique for both Cocks' and Zhao et al.'s cryptosystems.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Published elsewhere. SECITC 2023
Keywords
identity based encryptionquadratic residuosityoptimization
Contact author(s)
george teseleanu @ yahoo com
paulcotan @ gmail com
History
2023-11-03: approved
2023-11-01: received
See all versions
Short URL
https://ia.cr/2023/1693
License
Creative Commons Attribution-NonCommercial-ShareAlike
CC BY-NC-SA

BibTeX

@misc{cryptoeprint:2023/1693,
      author = {George Teseleanu and Paul Cotan},
      title = {Elementary Remarks on Some Quadratic Based Identity Based Encryption Schemes},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/1693},
      year = {2023},
      url = {https://eprint.iacr.org/2023/1693}
}
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