In order to achieve the dual functions of online/offline signcryption and broadcast signcryption,combining the thinking of online/offline signcryption and broadcast signcryption,an identity-based online/offline broadcast signcryption scheme was proposed.In this scheme,the offline stage is not irrelevant to the information that will be signcrypted,and in the online stage,the broadcast ciphertext will be generated and then sent to multi-receivers.During the scheme design,hash function operation, bilinear paring operation and Exclusive-OR operation were used.Based on some related cryptography hard problems,the scheme’s confidentiality and unforgery were testified under the random oracle model.Finally,the computation efficiency of the proposed scheme was analyzed.
