Cryptology ePrint Archive: Report 2019/1342

Scalable Wildcarded Identity-Based Encryption

Jihye Kim and Seunghwa Lee and Jiwon Lee and Hyunok Oh

Abstract: Wildcard identity-based encryption (WIBE) allows a sender to simultaneously encrypt messages to a group of users matching a certain pattern, defined as a sequence of identifiers and wildcards. We propose a novel scalable wildcarded identity-based encryption, called SWIBE, which reduces the ciphertext size to be constant. To the best of our knowledge, SWIBE is the first wildcard identity-based encryption scheme that generates a constant size ciphertext regardless of the depth of the identities with fast decryption. The proposed scheme improves the decryption time. According to our experiment results, decryption of the SWIBE scheme is 3, 10, and 650 times faster than existing WIBE, WW-IBE, and CCP-ABE schemes. The SWIBE scheme also subsumes the generalized key derivation naturally by allowing wildcards in the key delegation process. We prove CPA security of the proposed scheme and extend it to be CCA secure.

Category / Keywords: public-key cryptography / wildcard identity based encryption, constant ciphertext, key delegation, pattern

Original Publication (with minor differences): Euuropean Symposium on Research in Computer Security (ESORICS), 2018

Date: received 20 Nov 2019, last revised 24 Nov 2019

Contact author: jihyek at kookmin ac kr, ttyhgo at kookmin ac kr, jiwonlee at hanyang ac kr, hoh at hanyang ac kr

Available format(s): PDF | BibTeX Citation

Version: 20191125:063645 (All versions of this report)

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