The Design And Application Research Of Attribute-based Signature Schemes

Digital signature is an important part of information security technology and widely used for identity authentication,data integrity and non-repudiation.Digital signature technology is mainly used to resist active attack on the system,such as camouflage,spoofing,etc,thus is significant for key distribution,authentication in large network security communication.However,since the authentication method of traditional digital signature is one-to-one authentication,the distribution and management of keys would be extremely complex in large-scale environments.In addition,the data receiver knows the identity information of the data sender after verifying the signature,which is not conducive for the identity privacy of the user.Different from traditional digital signature,users in attribute-based signature no longer need to generate public-private key pairs separately.Each user is described by his attributes,obtaining the corresponding attribute signing key with these attributes,which reduces the expense of key distribution and management.In the signature verification phase,the data receiver verifies whether the data sender's attributes match the access structure.If so,The data sender is able to generate the valid signature,and the receiver can only get user's attributes,rather than infer the user's identity,which protects the identity privacy of the user.Therefore,attribute based signature can effectively implement security authentication and fine-grained access control,thus has drawn attention of academics.In terms of users' computation overhead,flexible access policy and key management cost issues,we design several attribute based signature schemes with distinct functional advantages for different applications.The main contributions of this work are listed as follows:1.In the electronic medical record environment,users' data may be updated frequently.If users have to generate signatures from scratch when data updating,it will cause heavy computational overhead to them.In order to solve this problem,an attributes based sanitizable signature scheme is proposed.We utilize a semi-trusted third-party sanitizer to modify the original signature according to the user's requirements and generate the new signature,and the user does not need to hand over the signing private key to the sanitizer.The proposed scheme is proved to be secure in the general group model.Through the experiments and comparison with existing work,the proposed scheme reduces the user's signing computation cost when data updating.2.The security of scheme in the generic group model is low,thus for the sake of improving the security level of algorithm,we propose an attribute based sanitizable signature scheme which is proved to be unforgeable against selective policy chosen message attack in the standard model.Comparison with the scheme above shows that the proposed scheme not only reduces users' computation cost,but also supports dendric access structure to achieve expressive access control for large-scale users.Performance analysis indicates that the number of group operations is reduced,which makes our scheme more efficient than the above-mentioned scheme.3.In the mobile healthcare system,users upload their health information with portable devices such as mobile phones.However,the computing resources of portable devices are very limited and cannot handle the medical data timely.To tackle the problem of excessive users' computation cost when their computation resources are limited,an outsourcing attribute based signature scheme for dendric access structure is proposed.Users can generate an outsourcing signature with the cloud computing platform in advance,which reduces users' computation cost.When uploading medical data,users can quickly combine the outsoucing signature with data at local to produce a final signature.In the standard model,it is proved that our scheme is unforgeable,and can resist selective attributes chosen message attack.Experiments indicate that the users' signing computation cost is reduced from linear size to constant size.4.Traditional attribute based signature utilizes the unique central authority to generate and distribute the user's attribute private key,which increases the computation overhead of the central authority.Meanwhile,the attributes of users may be from different authorities.In order to address the problems above,a multi-authority attribute based signature scheme supporting dendric access structure is proposed.We extend the unique central authority to multiple attribute authorities which issue the attribute private keys of attribute subdomains under their administration,respectively.We define a Global Identifier(GID)for each user to bind users with attribute signing keys,which prevents collusive attacks.Then we utilize the dendric access structure to achieve flexible fine-grained access control.In the random oracle model,the scheme is proved to be unforgeable against selective policy chosen message attack.