Signature‐policy attribute‐based key‐insulated signature
Y. Sreenivasa Rao · IET Information Security · 2016
Attribute‐based signature (ABS) schemes play a vital role to accomplish authentication and signer privacy simultaneously. In recent years, cryptographic primitives are deployed on insecure devices such as mobile devices; thereby, secret key exposure seems inevitable. To alleviate the impact of key exposure in ABS scenarios, the authors apply the method of key insulation to ABS and construct the first signature‐policy attribute‐based key‐insulated signature (ABKIS) scheme. The proposed construction supports expressive monotone Boolean functions as signing predicates and preserves signer privacy. Their ABKIS scheme is key‐insulated and strong key‐insulated secure under computational Diffie–Hellman exponent assumption. To the best of their knowledge, the proposed ABKIS is the first ABS scheme in signature‐policy flavour dealing with key exposure problems employing key‐insulation mechanism.