Data encryption methods include: one-way encryption, symmetric encryption, asymmetric encryption, hash encryption, SSL/TLS encryption, digital signature, digital timestamp, etc.

1. One-way encryption

The ciphertext is generated by summarizing the data, and the ciphertext cannot be restored reversibly. It can only encrypt but cannot decrypt. It is often used to extract fingerprint information of data to verify the integrity of the data.

2. Symmetric encryption

Use the same key to encrypt and decrypt data. Common algorithms include DES, AES, etc.

3. Asymmetric encryption

Use a pair of public key and private key to encrypt and decrypt data. Common algorithms include RSA, DSA, etc.

4. Hash encryption

The data is processed into fixed-length summary information through a hash algorithm. Common algorithms include MD5, SHA, etc.

5. SSL/TLS encryption

Use the public key to encrypt the symmetric key, and then use the symmetric key to encrypt the data. It is often used in the HTTPS protocol.