SymmetricAlgorithm

Represents the abstract base class from which all implementations of symmetric algorithms must inherit.

Derived

System.Security.Cryptography.Aes

System.Security.Cryptography.DES

System.Security.Cryptography.RC2

System.Security.Cryptography.Rijndael

System.Security.Cryptography.TripleDES

Rijndael Class  不推荐使用，建议使用Aes

Represents the base class from which all implementations of the Rijndael symmetric encryption algorithm must inherit.

Remarks

This algorithm supports key lengths of 128, 192, or 256 bits; defaulting to 256 bits. This algorithm supports block sizes of 128, 192, or 256 bits; defaulting to 128 bits (Aes-compatible).

The Rijndael class is the predecessor前辈 of the Aes algorithm. You should use the Aes algorithm instead of Rijndael. For more information, see the entry The Differences Between Rijndael and AES in the .NET Security blog.

Aes Class

Represents the abstract base class from which all implementations of the Advanced Encryption Standard (AES) must inherit.

Derived

System.Security.Cryptography.AesCng

System.Security.Cryptography.AesCryptoServiceProvider

System.Security.Cryptography.AesManaged

SymmetricAlgorithm 对称加密算法

原文：https://www.cnblogs.com/chucklu/p/12712219.html