File sharing method and system, electronic device and readable storage medium

A file sharing method, being applicable to a file owning end, comprising:

• obtaining a target file to be shared, and determining a first dynamic key corresponding to the target file;
• generating a first private key based on the first dynamic key and double private keys of the file owning end;
• selecting unpaired public and private keys from two pairs of public and private keys of the file owning end, and generating a first public key based on the first dynamic key, the selected public and private keys;
• encrypting a symmetric key selected randomly using the first public key to obtain a key ciphertext;
• encrypting the target file using the symmetric key to obtain a file ciphertext;
• signing the first dynamic key, the first public key, the key ciphertext and the file ciphertext using the first private key to obtain signature information;
• and
• uploading the first dynamic key, the first public key, the key ciphertext, the file ciphertext and the signature information as shared information to a cloud sharing end to share the target file.