## Cryptology ePrint Archive: Report 2016/125

Compact Identity Based Encryption from LWE

Daniel Apon and Xiong Fan and Feng-Hao Liu

Abstract: We construct an identity-based encryption (IBE) scheme from the standard Learning with Errors (LWE) assumption that has \emph{compact} public-key and achieves adaptive security in the standard model. In particular, our scheme only needs 2 public matrices to support $O(\log^2 \secparam)$-bit length identity, and $O(\secparam / \log^2 \secparam)$ public matrices to support $\secparam$-bit length identity. This improves over previous IBE schemes from lattices substantially.

Additionally, our techniques from IBE can be adapted to construct a compact digital signature scheme, which achieves existential unforgeability under the standard Short Integer Solution (SIS) assumption with small polynomial parameters.

Category / Keywords: public-key cryptography / Identity-Based Encryption

Date: received 11 Feb 2016, last revised 10 Oct 2016

Contact author: xfan at cs cornell edu

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2016/125

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