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Chapter 17: Security
The main drawback to TripleDES is that both the sender and receiver must use the
same key and initialization vector (IV) in order to encrypt and decrypt the data suc-
cessfully. If you wish to have an even more secure encryption scheme, use the
Rijndael scheme. This type of encryption scheme is highly regarded as a solid encryp-
tion scheme, since it is fast and can use larger key sizes than TripleDES. However, it
is still a symmetric cryptosystem, which means that it relies on shared secrets. Use an
asymmetric cryptosystem, such as RSA or DSA, for a cryptosystem that uses shared
public keys with private keys that are never shared between parties.
See Also
See the “SymmetricAlgorithm Class,” “TripleDESCryptoServiceProvider Class,” and
“RijndaelManaged Class” topics in the MSDN documentation.
17.4 Cleaning up Cryptography Information
Problem
You will be using the cryptography classes in the FCL to encrypt and/or decrypt
data. In doing so, you want to make sure that no data (e.g., seed values or keys) is
left in memory for longer than you are using the cryptography classes. Hackers can
sometimes find this information in memory and use it to break your encryption or,
worse, to break your encryption, modify the data, and then reencrypt the data and
pass it on to your ...