DES: DES is the abbreviation of Data Encryption Standard. This algorithm became the US government standard in 1977 and became the ANSI standard in 1981. DES encrypts block data with a 56-bit long key.
Triple-DES: Triple-DES repeats the DES algorithm three times with three incomplete KEYs, which can at least double the security. Repeating the secondary DES algorithm with two different KEYs does not improve the security to the average person. The degree of imagination, because the attacker can use DES to encrypt the plaintext while decrypting the generated ciphertext until DES is met.
RSA: RSA is by Ronald Rivest, Aid Shamir, Leonard
Adleman, a well-known public key system developed by three MIT professors. RSA can be used not only to encrypt information, but also as the basis of a digital signature system. The digital signature can be used to verify the source of the digital file, as well as the correctness of the content, and the KEY of the RSA can be of any length, depending on the actual situation.