The characteristics of symmetric encryption technology are as follows:

1. The encryption party and the decryption party use the same key.

2. The encryption and decryption speed is relatively fast, which is suitable for when the amount of data that needs to be encrypted is relatively large.

3. The key transmission process is unsafe and easy to be cracked, and key management is also troublesome.

The characteristics of asymmetric encryption technology are as follows:

1. Each user has a pair of key encryption: public key and private key.

2. Public key encryption, private key decryption; private key encryption, public key decryption.

3. Since the key length used by the public key is very long, the encryption speed of the public key is very slow, and it is generally not used to encrypt large amounts of data.

4. A certain user uses his own private key to encrypt, and other users use the user's public key to decrypt to achieve digital signature.

Asymmetric encryption algorithms run much slower than symmetric encryption algorithms. When a large amount of data needs to be encrypted, it is recommended to use symmetric encryption algorithms to increase the encryption and decryption speed. Symmetric encryption algorithms cannot implement signatures, so signatures can only use asymmetric algorithms.

Since the key management of the symmetric encryption algorithm is a complex process, the management of the key directly determines its security. Therefore, when the amount of data is small, it is still necessary to consider using an asymmetric encryption algorithm.