有向签名方案的分析和可转换扩展

Analysis and Convertibility Extension on Directed Signature Schemes

为保护用户的隐私,授权签名能够控制签名只有在签名者或可信第三方(TTP)的协助下由特定的验证者进行验证,有向签名是其中一种变型。然而,出于特定条件下除去验证限制的目的,签名者希望把同一类型的多个授权签名转换成自认证签名。通过改进QZX有向签名方案,使不可否认签名可以分别被TTP或者签名者协助验证,并同时具有批量转换和TTP监管的功能。

In order to protect user＇s privacy,Delegation signature scheme can force signatures to be convinced by the designated verifier only with the help of the signer or a trusted third party （TTP）,and directed signature scheme is one of the variants of delegation signature.However,for the sake of removing the limitation of verification under special conditlons,the signer is in need of the conversion capability of multiple delegation signatures according to the same conversion parameter.Two improved schemes are proposed based on the QZX directed signature schemes,which can be confirmed by either the signer or the confirmer.The schemes can satisfy requirements of both multiple signatures conversion and TTP supervision.