Secret key changing and signature updating method for cloud data audit

Abstract

The invention discloses a secret key changing and signature updating method for cloud data audit. The method comprises the following steps of a before-updating stage, an updating stage and an after-updating stage. In the before-updating stage, a data owner generates an initial secret key and a signature through calculation, a cloud server obtains initial data integrity authentication parameters through calculation according to the signature of the data owner and parameters received from the third audit party, and the third audit party is used for auditing the initial data integrity authentication parameters. In the updating stage, a data owner selects a random number generation secret key, calculates a secret key needed by a shared updated signature and sends the secret key to the cloud server, and the cloud server calculates a new signature according to data and the received parameters. In the after-updating stage, the data owner generates a signature through calculation according to the new secret key generated in the updating stage, the cloud server calculates new date integrity authentication parameters, and the third audit party is used for audit. The scheme guarantees safety and reduces cost of communication between the data owner and the server end and calculation cost of the data owner.

Description

technical field [0001] The invention relates to a safe and verifiable technology for data storage in cloud computing, specifically a new key change and signature update scheme. Background technique [0002] Today cloud computing is becoming more and more popular, where data is stored externally to the cloud. Its advantages are obvious: it eases the user's storage burden, enables universal data access independent of geographic location, and avoids hardware, software, and personal maintenance resource expenditures. However, outsourcing data creates new security concerns. The first problem is data integrity. The second problem is untrusted cloud service providers (CSP). [0003] In order to solve these two problems, we need evidence to show data owners and users that the CSP can save the data and will not be changed by any individual other than the user, which is called storage correctness requirement in the field, and will be designed to meet The scheme for storing correct...

AI Technical Summary

Problems solved by technology

However, outsourcing data creates new security concerns

The first problem is data integrity

The second problem is untrusted cloud service provider (CSP)

[0004] Existing verifiable storage schemes can provide good integrity protection for cloud data, but there is a resistance that prevents them from being widely used in cloud computing environments. When the data owner DO changes the expired key, DO must download Data block and signature, use the old key to confirm data integrity, generate a new signature with the new key, and upload the data block and new signature again

This will result in high communication expenditure for DO and cloud server CS and high computational expenditure for DO

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