Briefly talk about the principles and differences between symmetric encryption and asymmetric encryption

The principle of symmetric encryption is that the data sender processes the plaintext (original data) and encryption key together with a special encryption algorithm, turning it into a complex encrypted ciphertext and sending it out. After the receiver receives the ciphertext, if it wants to decipher the original text, it needs to use the encryption key and the inverse algorithm of the same algorithm to decrypt the ciphertext in order to restore it to readable plaintext.

The principle of asymmetric encryption is that Party A first generates a pair of keys and uses one of them as a public key; Party B, who obtains the public key, then uses the key to encrypt the information that needs to be encrypted. Then it is sent to Party A; Party A then uses another corresponding private key to decrypt the encrypted information, thus realizing confidential data transmission.

The difference between symmetric encryption and asymmetric encryption is: different keys, different security, and different digital signatures.

1. Different keys

1. Symmetric encryption: Symmetric encryption uses the same key for encryption and decryption.

2. Asymmetric encryption: Asymmetric encryption does not use the same key for encryption and decryption. Two keys are needed for encryption and decryption.

2. Different security

1. Symmetric encryption: If symmetric encryption is used to transmit encrypted files through the network, then no matter what method is used to tell the other party the key, it may be tapping.

2. Asymmetric encryption: Asymmetric encryption contains two keys, and only the "public key" can be disclosed. The recipient only needs to use the one he already holds. The private key is decrypted, so that security problems caused by the key during transmission can be well avoided.

3. Digital signatures are different

1. Symmetric encryption: Symmetric encryption cannot be used for digital signatures and digital authentication.

2. Asymmetric encryption: Asymmetric encryption can be used for digital signatures and digital authentication.