Researching Encryption in Windows and C# .NET

I was recently tasked with researching different methods of encryption for a license management module within my company and thought it might be useful to write down some of my findings. 

Cryptography has been around for a long time. Some of the more famous forms of old cryptography are in the Roman army, which used the "Caesar Cypher" to shift all letters to the left by three. "A" would become "X", "B" would become "Y", etc.

These days there are many more forms of data, and different ways to intercept it. Specifically we have data in-transit, and data at-rest.

For data-in-transit we use a public key private key method. The actual encryption of this method involves factoring extremely large numbers into their primes. If you're interested, this is a great video to watch.

With data-at-rest we use more complicated algorithms. In the Microsoft .NET library, these encryption methods are very well documented and held within the System.Security.Cryptography namespace. This includes methods for both in-transit and at-rest cryptography. 

Within the namespace there are two main encryption methods, Rijndael and Aes. The Microsoft Recommended method of encrypting data-at-rest is the AES method because Rijndael will not work when the FIPS-compliant security setting is enabled on a windows operating system. 

In conclusion, if you are encrypting a file, database, or some data on disk in a windows environment you should be using either the AesManaged, or AesCryptoServiceProvider classes from the System.Security.Cryptography namespaces.