C#

AES XTS Mode

See more Encryption Examples

Demonstrates the AES-XTS mode of operation.

Note: This example requires Chilkat v9.5.0.91 or greater.

C#

bool success = false;

//  This example assumes the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  Here we have a sample from CAVS validatition data:

//  COUNT = 301
//  DataUnitLen = 200
//  Key = 
//  394c97881abd989d29c703e48a72b397
//  a7acf51b59649eeea9b33274d8541df4
//  i = 4b15c684a152d485fe9937d39b168c29
//  PT = 2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0
//  CT = f3473802e38a3ffef4d4fb8e6aa266ebde553a64528a06463e

//  Note: The above sample requires an AES-XTS implementation that fully supports ciphertext-stealing
//  because the data to be encrypted is not an even multiple of the AES block size (i.e. not a multiple of 16 bytes).
//  Chilkat fully supports AES-XTS with ciphertext stealing.
//  (i.e. Chilkat implements XEX-based tweaked-codebook mode with ciphertext stealing (XTS))

string key = "394c97881abd989d29c703e48a72b397";
string tweakKey = "a7acf51b59649eeea9b33274d8541df4";
string dataUnit = "4b15c684a152d485fe9937d39b168c29";

Chilkat.BinData bd = new Chilkat.BinData();
bd.AppendEncoded("2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0","hex");

Chilkat.Crypt2 crypt = new Chilkat.Crypt2();

crypt.CryptAlgorithm = "aes";
crypt.CipherMode = "xts";
crypt.KeyLength = 128;

crypt.SetEncodedKey(key,"hex");
crypt.XtsSetEncodedTweakKey(tweakKey,"hex");
crypt.XtsSetEncodedTweakValue(dataUnit,"hex");

//  In-place encrypt the contents of bd.
success = crypt.EncryptBd(bd);

Debug.WriteLine("CT = " + bd.GetEncoded("hexlower"));

//  Decrypt to revert back to the unencrypted content:
success = crypt.DecryptBd(bd);

Debug.WriteLine("PT = " + bd.GetEncoded("hexlower"));

//  Output:
//  CT = f3473802e38a3ffef4d4fb8e6aa266ebde553a64528a06463e
//  PT = 2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0