CAJ | 학술논문

针对陈瑞虎等人提出的门限共享验证签密方案(微计算机信息,2005年第11期),给出针对该方案的攻击算法。基于椭圆曲线提出一种改进的前向安全门限共享解签密方案,证明方案的机密性、不可伪造性与不可否认性。该方案具有门限完备性、抗合谋攻击等安全特性,并且当签密密钥泄漏时,攻击者无法得到对称密钥恢复明文,也无法从之前的签密密文中获得秘密信息,具有签密的前向安全性。分析结果表明,改进方案的整体运算量及签密密文长度小于陈瑞虎等人提出的方案,门限解签密算法的运算及通信效率得到明显提高。
침대진서호등인제출적문한공향험증첨밀방안(미계산궤신식,2005년제11기),급출침대해방안적공격산법。기우타원곡선제출일충개진적전향안전문한공향해첨밀방안,증명방안적궤밀성、불가위조성여불가부인성。해방안구유문한완비성、항합모공격등안전특성,병차당첨밀밀약설루시,공격자무법득도대칭밀약회복명문,야무법종지전적첨밀밀문중획득비밀신식,구유첨밀적전향안전성。분석결과표명,개진방안적정체운산량급첨밀밀문장도소우진서호등인제출적방안,문한해첨밀산법적운산급통신효솔득도명현제고。
This paper analyzes the threshold signcryption scheme of Chen et al ( Microcomputer Information,2005, No. 11),and proposes its attack algorithm. Then it presents an efficient threshold unsigncryption scheme with forward security based on elliptic curve and analyzes the confidentiality,unforgeability,non-repudiation and additional properties of the scheme,including perfect secret sharing,coalition attack resistance and forward security. Analysis result shows that the improved threshold unsigncryption scheme achieves high efficiency regarding practical application with its much lower cost of computation and communication and shorter signcryption text than the scheme by Chen et al.