File encryption method based on blockchain bidding and tendering system

The invention discloses a file encryption method based on a blockchain bidding and tendering system, comprising the following steps: 1) a bidder imports a bidding file F into a client, and the clientrandomly generates an AES key and encrypts the F by using an AES algorithm to generate F '; 2) the client uploads F'to an IPFS, the client takes a hash value of F 'to obtain Hf, a random number uuid is added behind Hf to obtain m, a blind signature algorithm is applied to blinding the m, and m' is obtained; 3) the client sends m' to a server for signature, and the server signs m' by using a private key to obtain s'; 4) the client sends s' to the intelligent contract, and the intelligent contract is used for verify the validity of the signature of the bidding party; if the signature is valid, the client removes blindness of the s' to obtain s; if the signature is invalid, step 3) is executed; 5) the client sends s and m to the intelligent contract for verification; if the verification succeeds, m is stored in the b