CN112560071A - Data sharing method with functions of auditing and designating verifier - Google Patents

Abstract

The invention discloses a data sharing method with functions of auditing and designating verifiers. The invention has three types of participants, namely a data owner, a data auditor and a data user. The data owner shares own data to the data user. The data auditor will audit the shared data and modify it according to the regulations. To ensure the authenticity of the data, the data owner needs to digitally sign the data before sending it. When the data needs to be modified, the data auditor does not need to interact with the data owner, and the data auditor directly modifies the data and generates a corresponding new digital signature. Only the data consumer can verify the source of the data, i.e. only the data consumer can verify the validity of the digital signature.

Description

Data sharing method with functions of auditing and designating verifier

Technical Field

The invention belongs to the technical field of information security, and relates to a data sharing method with functions of auditing and designating a verifier.

Background

At present, people pay more and more attention to the security problem of mass data storage of computers and the anti-theft and anti-tampering problems of sensitive data. The database system is used as a core component of a computer information system, and the database file is used as an aggregate of information, so that the security of the database system is important in the information industry. In order to ensure the security of the database, for some applications in important departments or sensitive fields, it is necessary to encrypt important data stored in the database.

After the database is encrypted, the database system often needs to give different users different usage rights. The traditional key distribution and management mechanism is difficult to distinguish users with different use authorities, and can not prevent legal users from using the database without the right, nor verify the illegal use of the database by the users. By adopting a digital signature technology in the modern cryptographic technology, security protection can be implemented on an encryption key and an authorization certificate of the database, and a legal user can access the database according to authorization after providing a correct authorization certificate.

In a data sharing system using conventional digital signatures, when data needs to be modified, a data auditor must interact with a data owner, modify the data, and re-sign the data.

In a data sharing system using modifiable digital signatures, anyone can verify the authenticity of the data, which to some extent reveals privacy, i.e. where the data came from. In a data sharing system, only the data user needs to be able to verify the source of the data.

Disclosure of Invention

The invention provides a data sharing method with functions of auditing and designating verifiers, aiming at the defects of the prior art.

The technical scheme of the invention is as follows:

the invention comprises the following steps:

step 1, generating system parameters

The system parameters comprise: bilinear group with large prime number q

And bilinear mapping thereon

One generator g, and two hash functions H:

and H':

step 2, the data owner is selected from

Randomly selecting a random number x as a signature private key and calculating

Wherein

Is an integer in the range of 1 to (q-1);

the data owner discloses a signature verification public key pk ═ y of the data owner, and reserves a signature private key sk ═ x of the data owner;

step 3, the data auditor

Randomly selecting a random number v as a data modification private key and calculating a data modification public key

The data auditor discloses a data modification public key u and reserves a data modification private key v of the data auditor;

step 4, the data user slave

Randomly selects a random number x' as a private key, and calculates a public key of a data user

The data user discloses a public key y 'of the data user and reserves a private key x' of the data user;

step 5, when the data m needs to be shared, the data owner carries out digital signature on the data m to be shared, and the data owner does the following operations:

a) from

Randomly selecting a random number r;

b) computing

c) Computing

d) Setting (r, sigma) as a digital signature of the data m, and marking sig as (r, sigma);

e) sending the data m and the digital signature sig thereof to a data auditor;

step 5, when the data auditor receives the data m and the digital signature sig thereof, the data m is audited correspondingly;

if the verification is passed, the data m and the digital signature sig thereof are forwarded to a data user;

if the audit is not passed, the following operations are carried out:

f) each data auditing entity computing

g) Setting (r ', σ) as a digital signature of the data m', and marking as sig '═ r', σ;

h) sending the data m 'and the digital signature sig' thereof to a data user;

step 6, after receiving the data m 'and the digital signature sig' thereof, the data user verifies the validity of the data m 'and the digital signature sig', and if the following equation is established, the signature is valid;

the invention has the beneficial effects that:

1. when the data needs to be modified, the data auditor does not need to interact with the data owner, and the corresponding new digital signature is directly modified and generated.

2. Only the data consumer can verify the source of the data, i.e. only the data consumer can verify the validity of the digital signature.

Drawings

FIG. 1 is a flow chart of the method of the present invention.

Detailed Description

There are three types of participants in the present invention, data owner, data auditor and data user respectively. The data owner shares own data to the data user. The data auditor will audit the shared data and modify it according to the regulations. To ensure the authenticity of the data, the data owner needs to digitally sign the data before sending it. In addition, in the present invention, a plurality of data owners, a plurality of data auditors, and a plurality of data users may exist simultaneously.

The specific steps of the present invention are described in detail below with reference to fig. 1:

step 1, system parameter generation (this step may be performed by an authority).

The system parameters include: bilinear group with large prime number q

And bilinear mapping thereon

One generator g, and two hash functions H:

and H':

all people in the system know these system parameters.

Wherein the bilinear map is defined in bilinear groups

A mapping of (a). In particular, the present invention relates to a method for producing,

is a finite cyclic group of order large prime number q, mapped

The following three conditions are satisfied:

1. bilinear: for the

Is provided with

2. Non-degradability: exist of

So that

3. Scientific and technological acidity: for any

There is one same efficient algorithmic calculation

When in use

At first, call

Symmetric bilinear mapping, otherwise referred to as asymmetric bilinear mapping.

Step 2, the data owner is selected from

Randomly selecting a random number x and calculating

The data owner discloses its signature verification public key pk ═ y, but retains its own signature private key sk ═ x.

Step 3, the data auditor

Randomly selecting a random number v and calculating

The data auditor discloses its data modification public key u, but retains its own data modification private key v.

Step 4, the data user slave

Randomly selecting a random number x' and calculating

The data consumer publishes its public key y 'but retains its own private key x'.

And 5, when data needs to be shared, the data owner carries out digital signature on the data.

Assuming that the data to be shared is m, the data owner does the following:

a) from

Randomly selecting a random number r;

b) computing

c) Computing

d) Setting (r, sigma) as a digital signature of the data m, and marking sig as (r, sigma);

e) and sending the data m and the digital signature sig thereof to a data auditor.

And 6, when the data m and the digital signature sig thereof are received by the data auditor, carrying out related audit on the data m. If the verification is passed, the data m and the digital signature sig thereof are forwarded to the data user. If the audit is not passed, the following operation is performed (assuming that the modified data is m')

f) Each data auditing entity computing

g) Setting (r ', σ) as a digital signature of the data m', and marking as sig '═ r', σ;

h) and sending the data m 'and the digital signature sig' thereof to a data user.

And 6, after receiving the data and the digital signature thereof, the data user verifies the validity of the data and the digital signature thereof. According to the above step, it can be known that the data and the digital signature received by the data user may be m and sig, or m 'and sig'. But mathematically, both cases are essentially the same, so that the validity of the signature can be verified by the following equation.

Claims (1)

1. A data sharing method having a function of auditing and designating verifiers, characterized by comprising the steps of:

step 1, systemGenerating system parameters, wherein the system parameters comprise: bilinear group with large prime number q

And bilinear mapping thereon

One generator g of (1), and two hash functions

And

step 2, the data owner is selected from

Randomly selecting a random number x as a signature private key and calculating

Wherein

Is an integer in the range of 1 to (q-1);

the data owner discloses a signature verification public key pk ═ y of the data owner, and reserves a signature private key sk ═ x of the data owner;

step 3, the data auditor

Randomly selecting a random number v as a data modification private key and calculating a data modification public key

The data auditor discloses a data modification public key u and reserves a data modification private key v of the data auditor;

step 4, the data user slave

Randomly selects a random number x' as a private key, and calculates a public key of a data user

The data user discloses a public key y 'of the data user and reserves a private key x' of the data user;

step 5, when the data m needs to be shared, the data owner carries out digital signature on the data m to be shared, and the data owner does the following operations:

a) from

Randomly selecting a random number r;

b) computing

c) Computing

d) Setting (r, sigma) as a digital signature of the data m, and marking sig as (r, sigma);

e) sending the data m and the digital signature sig thereof to a data auditor;

step 5, when the data auditor receives the data m and the digital signature sig thereof, the data m is audited correspondingly;

if the verification is passed, the data m and the digital signature sig thereof are forwarded to a data user;

if the audit is not passed, the following operations are carried out:

f) each data auditing entity computing

g) Setting (r ', σ) as a digital signature of the data m', and marking as sig '═ r', σ;

h) sending the data m 'and the digital signature sig' thereof to a data user;

step 6, after receiving the data m 'and the digital signature sig' thereof, the data user verifies the validity of the data m 'and the digital signature sig', and if the following equation is established, the signature is valid;

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