The invention discloses a traceable effective open auditing method in cloud storage data sharing, and a cloud computing application system. The method comprises the following steps: initializing the system, generating a main private key and open parameters by using an attribute mechanism, allocating an attribute private key to each user, and embedding the user identity in the attribute private key; formulating a signature strategy by a data owner, generating a label for a data block, and uploading the label to a cloud server; modifying the data by a user satisfying the signature strategy; verifying the label of the modified data by the cloud server; sending challenge to the cloud server by a verifier; calculating auditing evidence by the cloud server, and returning the auditing evidence to the verifier; verifying the correctness of the evidence by the verifier; and tracing the malicious user. According to the traceable effective open auditing method disclosed by the invention, the privacy of the user identity is protected in a multi-user data sharing environment, the traceability of the malicious user is realized at the same time, and the storage overhead for tracing is a constant.

Traceable effective open auditing method and system in cloud storage data sharing

The invention discloses an anonymous message sending system and method used for auditing and tracking. The system includes: a registration module, which is used for generating user credentials throughinteraction of users and a registration organization (Manager), a signature module, which is used for obtaining a linkable group signature in communication through the users, a verification module, which is used for verifying validity of the linkable group message signature; a linking module, which is used for judging, in a linking manner, whether any two messages are from the same user; and a tracking module, which is used for tracking associated users of abnormal messages. According to the system, privacy protection of communication senders can be effectively realized through a linkable group signature scheme, auditing of an auditing organization (Linker) on the abnormal messages is realized, tracking of a supervision organization (Tracer) on the users is realized, information securityof a communication system is protected, personal privacy is protected, and security supervision is improved.

Anonymous message sending system and method used for auditing and tracking

The invention discloses a theoretically secure flexible multi-secret sharing method. The method comprises the following steps: performing initialization; selecting random numbers and transmitting the random numbers to participants; selecting m arbitrary points; obtaining a polynomial with an order of n+m-1 by using the Lagrange difference method; randomly selecting different integers in the residual domain, and substituting the integers in the polynomial for calculation; opening the abscissas of the selected points and the calculated value of the polynomial; calculating cj1, cj2,... cjm by the participant Pj according to the known information; for a secret S1, selecting rj1, rj2, ... rjt by the participant Pj, wherein arbitrary t participants can reconstitute the secret; calculating an intermediate value rl for restoring the secret by the participant Pj, and sending the intermediate value to all the other participants; and calculating the secret S1. By adoption of the theoretically secure flexible multi-secret sharing method disclosed by the invention, multiple secrets can be shared at a time, so that the efficiency is relatively high, and the secret sharing is more efficient.

Theoretically secure flexible multi-secret sharing method

The invention discloses a tamper-proof storage method of electronic material evidence based on group signature. The method is based on group signature technology, and can ensure that electronic material evidence is not tampered with maliciously under the condition that erroneous data need to be modified or electronic material evidence data need to be added in the later period through the combination of software and hardware, and has good forgery-proof property and usability. The method adopts the disk array as the data mirror, which can effectively improve the authenticity and integrity of theelectronic material evidence data.

A tamper-proof storage method of electronic material evidence based on group signature

The invention discloses an integrity public verification protocol of shared data in certificateless cloud storage. a data label is generated for all data blocks by referring to a certificateless signature mechanism, and user part private key information, user secret value information and original data block file information are embedded into the data label. the data block together with the corresponding data label is uploaded to a cloud storage. And all the group members can execute the operations of accessing, modify, delet the data and the like, and regenerate corresponding verification tags. And when the verifier verifies that the data is complete, a challenge is initiated to the cloud server. the cloud server generates an integrity evidence by using the stored data block information and the corresponding tag information, and returns the integrity evidence to the verifier. The verifier verifies the validity of the evidence by using the public information and judges whether the datais complete. a revocation request is sent when the members in the group leave the organization, and label updating of the to-be-revoked user is completed with the help of the cloud storage server. Theprotocol is oriented to public integrity verification of data, supports member revocation, avoids work of secret key hosting, digital certificate management and the like, and is safe and efficient.

An integrity public verification protocol for shared data in a certificateless cloud storage

The invention discloses a public auditing method with privacy protection for shared data of a multi-manager group, which comprises the steps of (1) system establishment; (2) user registration; (3) user cancellation; (4) data signature generation; (5) audit challenge; (6) audit certification; (7) audit verification; and (8) user tracking. According to the invention, a homomorphous verifiable group signature scheme supporting multiple managers is constructed based on a forward-security cancelable group signature and (t, s) secret sharing, thereby having high efficiency; the integrity of outsourced data is confirmed in allusion to a cloud server; and the identity privacy of group users is protected in allusion to an auditor, the identity of the users is traceable, and the whole tracing process is fair, so that the users are not maliciously framed.

Zhang Gongxuan

Papers

Public auditing method with privacy protection for shared data of multi-manager group