Introduction to Symmetric and Asymmetric C# with Example

Encryption 
You can improve the security for data transit or storing by implementing encrypting techniques. Basically there are 
two approaches when using System.Security.Cryptography: symmetric and asymmetric. 
Symmetric Encryption 
This method uses a private key in order to perform the data transformation. 
Pros: 
Symmetric algorithms consume less resources and are faster than asymmetric ones. 
The amount of data you can encrypt is unlimited. 
Cons: 
Encryption and decryption use the same key. Someone will be able to decrypt your data if the key is 
compromised. 
You could end up with many different secret keys to manage if you choose to use a different secret key for 
different data. 
Under System.Security.Cryptography you have different classes that perform symmetric encryption, they are 
known as block ciphers: 
AesManaged (AES algorithm). 
AesCryptoServiceProvider (AES algorithm FIPS 140-2 complaint). 
DESCryptoServiceProvider (DES algorithm). 
RC2CryptoServiceProvider (Rivest Cipher 2 algorithm). 
RijndaelManaged (AES algorithm). Note: RijndaelManaged is not FIPS-197 complaint. 
TripleDES (TripleDES algorithm). 
 

Asymmetric Encryption 
This method uses a combination of public and private keys in order to perform the data transformation. 
Pros: 
It uses larger keys than symmetric algorithms, thus they are less susceptible to being cracked by using brute 
force. 
It is easier to guarantee who is able to encrypt and decrypt the data because it relies on two keys (public and 
private). 
Cons: 
There is a limit on the amount of data that you can encrypt. The limit is different for each algorithm and is 
typically proportional with the key size of the algorithm. For example, an RSACryptoServiceProvider object 
with a key length of 1,024 bits can only encrypt a message that is smaller than 128 bytes. 
Asymmetric algorithms are very slow in comparison to symmetric algorithms. 
Under System.Security.Cryptography you have access to different classes that perform asymmetric encryption: 
DSACryptoServiceProvider (Digital Signature Algorithm algorithm) 
RSACryptoServiceProvider (RSA Algorithm algorithm)