Visible to the public Efficient Construction for Full Black-Box Accountable Authority Identity-Based Encryption

TitleEfficient Construction for Full Black-Box Accountable Authority Identity-Based Encryption
Publication TypeJournal Article
Year of Publication2019
AuthorsZhao, Zhen, Lai, Jianchang, Susilo, Willy, Wang, Baocang, Hu, Yupu, Guo, Fuchun
JournalIEEE Access
KeywordsA-IBE scheme, Accountable authority, attribute-based encryption, authorisation, authority identity-based encryption, black box encryption, black-box security, ciphertexts, composability, computational complexity, data privacy, decoder box, Decoding, dummy identity-based encryption, Encryption, full black-box security, generic construction, Identity-based encryption, malicious private key generator, Metrics, private key cryptography, pubcrawl, resilience, Resiliency, token-based identity-based encryption, underlying TB-IBE scheme, user decryption, user identity, user privacy security, user private key

Accountable authority identity-based encryption (A-IBE), as an attractive way to guarantee the user privacy security, enables a malicious private key generator (PKG) to be traced if it generates and re-distributes a user private key. Particularly, an A-IBE scheme achieves full black-box security if it can further trace a decoder box and is secure against a malicious PKG who can access the user decryption results. In PKC'11, Sahai and Seyalioglu presented a generic construction for full black-box A-IBE from a primitive called dummy identity-based encryption, which is a hybrid between IBE and attribute-based encryption (ABE). However, as the complexity of ABE, their construction is inefficient and the size of private keys and ciphertexts in their instantiation is linear in the length of user identity. In this paper, we present a new efficient generic construction for full black-box A-IBE from a new primitive called token-based identity-based encryption (TB-IBE), without using ABE. We first formalize the definition and security model for TB-IBE. Subsequently, we show that a TB-IBE scheme satisfying some properties can be converted to a full black-box A-IBE scheme, which is as efficient as the underlying TB-IBE scheme in terms of computational complexity and parameter sizes. Finally, we give an instantiation with the computational complexity as O(1) and the constant size master key pair, private keys, and ciphertexts.

Citation Keyzhao_efficient_2019