What is an electronic signature

At present, electronic signatures can be implemented through a variety of technical means. After confirming the exact identity of the signer, the electronic signature recognizes that people can sign an electronic record in a variety of different ways. Methods include: digital signatures based on PKI-based public-key cryptography; identification based on biometric statistics; recognition of fingerprints, sound imprints, or retina scans; and a password code that allows the recipient to identify the sender's identity. PIN or personal identification number PIN; computer based on quantum mechanics, etc. However, more mature, easy to use and operable, electronic signature technology commonly used in the world's advanced countries and China is based on PKI (Public Key Infrastructino) digital signature technology.

1. Pattern recognition of handwritten signatures or stamps

A handwritten signature or seal is used as an image, scanned by light and stored in a database. When the person is verified, the input is scanned with light, and the corresponding image in the original database is called. Mathematical calculation using pattern recognition Method to compare to confirm the authenticity of the signature or seal. This method was once used at the bank accounting desk. Due to the need for large-capacity database storage and the difference between each handwritten signature and stamping, this method proved to be unsuitable for transmission over the Internet.

2. Biometric technology

Biometrics technology is a technology that uses human biometrics for identity authentication. Biometrics are unique representations of a person and others, which can be measured, automatically identified, and verified. The biometric system samples biological features, extracts their unique features, digitizes them, converts them into digital codes, and further stores these code constituent feature templates in a database. When people interact with the recognition system to perform identity authentication, the recognition system acquires them. The features are compared with the feature templates in the database to determine if they match and thus decide to confirm or deny the person. Biometric technologies mainly include the following types:

(1) Fingerprint identification technology. Each person's fingerprint skin pattern is unique and does not change for life. By comparing his fingerprint with the fingerprint stored in the database in advance using a fingerprint recognition algorithm, his true identity can be verified. Under the premise of identification, paper documents or data messages can be signed by handprint or signed in the IC card. This type of signature requires large database support, which is suitable for local face-to-face processing and is not suitable for online transmission.

(2) Retina recognition technology. The retina recognition technology uses a laser to irradiate the back of the eyeball, scans and captures the feature points of several hundred retinas, and after digital processing forms a memory template stored in a database for later comparison verification. The retina is an extremely stable biometric, and identity authentication is a highly accurate identification technique. However, it is difficult to use for direct digital signatures and network transmission.

(3) Voice recognition technology. Voice recognition technology is a kind of behavior recognition technology. It uses audio recording equipment to repeatedly measure and record the changes of sound waveforms, perform spectrum analysis, and after digital processing, makes a sound template to store. When used, the sound collected at the scene is accurately matched with the registered sound template to identify the identity. This technique is less accurate and difficult to use and does not apply to direct digital signatures and network transmissions.

The above identification methods are suitable for face-to-face situations. Remote network authentication and large-scale crowd authentication are not applicable.

3, password, password code or personal identification code

Traditional symmetric key encryption/decryption methods for identification and signature. Party A needs Party B to sign an electronic file. Party A can generate a random code and send it to Party B. Party B encrypts the random code and electronic file with Party A's previously agreed symmetric key and sends it back to Party A. Party A uses the same symmetric key. After decryption, the message is obtained and the random code is checked. If the random code is verified correctly, Party A can consider the message as coming from Party B. For remote network transmission, symmetric key management is difficult and is not suitable for large-scale crowd authentication.

In symmetric key encryption/decryption authentication, ID+PIN (identity unique identifier+password) is often used in practical applications. That is, the sender encrypts the ID and PIN with the symmetric key and sends it to the receiver. The receiver decrypts and compares the ID and password stored in the background to achieve the purpose of authentication. The bank card used by people in daily life is the authentication method used. For remote network transmission, symmetric key management is difficult and does not apply to electronic signatures.

4. Computer based on quantum mechanics

A quantum computer is a computer that directly computes on the principle of quantum mechanics. It uses a new quantum cryptography coding method that uses the phase characteristics of photons. Since the randomness of quantum mechanics is very special, no matter how smart the eavesdropper is, it will leave traces when deciphering the password, and even when the password is eavesdropped, it will automatically change. It can be said that this will be the safest password authentication and signature method in the world. However, this kind of computer still only stays in the stage of theoretical research and is still far from the actual application.

5, PKI-based electronic signature

PKI (Public Key Infrastructure) based electronic signatures are called "digital signatures." Some people claim that "electronic signature" is "digital signature" is wrong. Digital signatures are only a special form of electronic signatures. Because electronic signatures are technically neutral, they also bring inconvenience to use. The electronic signatures are further stipulated in law, such as the above-mentioned UNCTAD’s “E-signature Model Law” and the European Union’s “E-signature common framework”. The "Regulations" stipulates "reliable electronic signatures" and "advanced electronic signatures." In fact, it is a function that provides digital signatures. This provision makes digital signatures have better application security and operability. At present, the only meaningful electronic signature is the public key cryptography theory. Therefore, the PKI-based digital signature technology is widely used at home and abroad, and is mature and practical. As a public key infrastructure PKI can provide a variety of online security services such as authentication, data confidentiality, data integrity and non-repudiation. Both use digital signature technology. This is also the focus of this article.