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1. Symmetric encryption:
Symmetric encryption, that is, the use of symmetric password encoding technology, his feature is that encryption and decryption use the same key.
Common symmetric encryption algorithms are DES, 3DES, Blowfish, IDEA, RC4, RC5, RC6 and AES. Symmetric encryption algorithms are simple and quick to use, have short keys, and are difficult to decipher.
However, the following problems exist in the use of symmetric keys:
1. Symmetric encryption algorithms generally cannot provide authentication of information integrity. It cannot verify the identity of the sender and receiver;
2. The management and distribution of symmetric keys is a potentially dangerous and cumbersome process. How to prevent secret key leakage is a difficult point.
2. Asymmetric encryption:
Asymmetric encryption technology requires two secret keys, a public key and a private key. The public key and private key appear in pairs.
If the public key is used to encrypt data, only the corresponding private key can be used to decrypt; if the private key is used to encrypt data, then only the corresponding public key can be used to decrypt. Because encryption and decryption use two different keys, this algorithm is called an asymmetric encryption algorithm.
The basic process of asymmetric encryption algorithm to realize the exchange of confidential information is: Party A generates a pair of keys and exposes one of them as a public key to other parties; Party B who has obtained the public key uses this key to conduct confidential information After encryption, it is sent to Party A; Party A then uses another private key saved by itself to decrypt the encrypted information. Party A can only use its private key to decrypt any information encrypted by its public key.
The typical application of asymmetric encryption is digital signature.
Common asymmetric encryption algorithms are: RSA, ECC (for mobile devices), Diffie-Hellman, El Gamal, DSA (for digital signatures).