What Does a Signing Agent Do?

Proxy signature means that in a proxy signature scheme, a designated proxy signer can generate a valid signature on behalf of the original signer.

Proxy signature

Right!

Proxy signature means that in a proxy signature scheme, a designated proxy signer can generate a valid signature on behalf of the original signer.

Chinese name

Proxy signature

Foreign name

Agent Signature Scheme

Meaning

Some agent signs on his own behalf

Problem

safety(

For example, Director A needs to travel, and these places do not have good access to the computer network. So A wants to receive some important e-mails and instructs his secretary B to respond accordingly. Without giving his private key to B, A can ask B to proxy. This proxy has the following characteristics:

Anyone can distinguish between proxy signatures and normal signatures.

Unforgeable. Only the original signer and the designated proxy signer can generate a valid proxy signature.

The proxy signer must create a valid proxy signature that can be detected as a proxy signature.

Verifiability. From the proxy signature, the verifier can be confident that the original signer agreed with the signed message.

Recognizability. The original signer is able to identify the proxy signer from the proxy signature.

Undeniable. A proxy signer cannot deny a proxy signature established and recognized by him.

First, several issues to consider when entrusting digital signature authority

(1) Security.

Abuse of power and resistance to attack are not allowed.

(2) Practicability.

Convenient and effective, easy to implement.

(3) Efficiency.

Higher implementation speed, less computational complexity, communication complexity, etc.

Descriptive definition of proxy signatures

A proxy signature is: the original signer authorizes his signing power to the proxy signer, and then asks the proxy signer to generate a valid signature on behalf of the original signer.

It contains the following sections:

1, the initialization process; (the parameters of the signature system, the user's key, etc.)

2. Power delegation process;

3. Proxy signature generation process;

4. Proxy signature verification process.