Abstract: Aiming at the problem of linear ciphertext increase of current fuzzy-attribute based signcryption schemes with attribute number, a fuzzy attribute based signcryption scheme with constant length ciphertext is proposed. This scheme is constructed based on Lagrange interpolation formula and bilinear pairings. Signcrypter can signcrypt a message and send the resulting ciphertext to a set of users who own a designated attributes set, and ensure the secure properties, such as confidentiality and unforgeability of the message. Compared with current similar fuzzy attribute-based schemes, this scheme requires less computation resources. The ciphertexts length is constant in the scheme. Thus, it has better efficiency.

Key words: attribute-based, signcryption, constant length, multi-users, bilinear pairings

摘要： 针对目前模糊属性基签密方案密文长度随属性个数线性增加的问题，提出了一个密文长度为常数的模糊属性基签密方案。该方案利用拉格朗日插值公式和双线性对进行构建。签密者可将一段消息签密后发送给具有指定属性集的多个用户，同时保证消息的机密性、不可伪造性等安全属性。和现有同类模糊属性基方案相比，该方案需要的运算量最少，并同时支持常数长度的密文，具有更好的效率。

关键词: 属性基, 签密, 常数长度, 多用户, 双线性对