Legal analysis: the CA certificate in electronic bidding essentially replaces the original official seal of the unit. The tenderer requires the paper documents to be scanned into electronic documents after being stamped with the official seal of the company. They are just electronic copies of paper documents. Without electronic signatures, they have no legal effect in electronic bidding.

However, for some types of documents, it is still reasonable and necessary for the tenderer to require the use of paper scanned copies. For example, the third-party documents such as the power of attorney of the manufacturer, bank credit certificate, etc. must be signed or sealed by qualified legal subjects, then scanned and put into the bidding documents, and finally signed and encrypted with CA certificates to form effective electronic bidding documents.

Legal basis: Bidding Law of People's Republic of China (PRC).

Article 9 If a project subject to tender needs to go through the project examination and approval procedures in accordance with the relevant provisions of the state, it shall go through the examination and approval procedures first and obtain approval.

The tenderer shall have the corresponding funds for the project subject to tender or the sources of funds have been implemented and truthfully stated in the tender documents.

Article 10 Bidding is divided into open bidding and invitation bidding.

Open tender means that the tenderer invites unspecified legal persons or other organizations to bid by means of tender announcement.

Invitation to bid means that a tenderer invites a specific legal person or other organization to bid in the form of an invitation to bid.