According to the provisions of the Electronic Signature Law on reliable electronic signatures, the electronic signature of "locking the real identity of the contracting party, effectively preventing document tampering and accurately recording the signing time" is an electronic signature with legal effect.

Electronic contract records the signing time by time stamp technology, which is an important element to ensure the legal effect of electronic contract.

Time is very important information in e-commerce transaction documents. In a written contract, the date of signing the document is as important as the signature to prevent the document from being forged and tampered with.

Digital timestamp service is one of the online e-commerce security services, which can provide security protection for the date and time information of electronic files. A time stamp, usually a series of characters, uniquely identifies the time at a certain moment.

Digital time stamp technology is a variant of digital signature technology, which is usually used in digital signature systems. Existing CA institutions also provide time stamp service when applying for digital certificates to ensure that time information is not tampered with or forged. However, an institution that only provides time stamp service but not digital certificate service in the market is not an "electronic authentication service provider" as mentioned in the Electronic Signature Law, because it has not obtained an electronic authentication service license issued by the Ministry of Industry and Information Technology, nor can it prove the subject identity of the document signer or service user, which has limitations in technology and legal effect.