中文摘要：

为了降低门限解签密算法的计算开销,基于离散对数问题提出了一种新的门限解签密方案。该方案通过随机数和私钥生成签密密钥来签密消息,引入门限共享思想获取解签密钥来恢复消息。与现有方案相比,该方案的计算开销明显较小。在离散对数假设和DDH假设的前提下,该方案满足机密性、不可伪造性、不可否认性和不相关性。

英文摘要：

In order to reduce the computational cost of the algorithm, a new threshold unsigneryption scheme based on DLP （discrete logarithm problem） is proposed. In the scheme, the key of the signcryption is generated by the random number and the private key to sign the message. Furthermore, the key of the unsigncryption is gained by introducing the threshold sharing to recover the message. Compared with the existing schemes, the computational cost of the proposed scheme is obviously smaller. On the premise of DLP assumption and DDH assumption, the scheme has been proved to satisfy confidentiality, unforgeability, non-repudiation and non-correlation.