C# SHA1 Example

using System.Security.Cryptography;

/// <summary>
/// Calculates SHA1 hash
/// </summary>
/// <param name="text">input string</param>
/// <param name="enc">Character encoding</param>
/// <returns>SHA1 hash</returns>
public static string CalculateSHA1(string text, Encoding enc)
{
    // Convert the input string to a byte array
    byte[] buffer = enc.GetBytes(text);

    // In doing your test, you won't want to re-initialize like this every time you test a
    // string.
    SHA1CryptoServiceProvider cryptoTransformSHA1 =
    new SHA1CryptoServiceProvider();

    // The replace won't be necessary for your tests so long as you are consistent in what
    // you compare.
    string hash = BitConverter.ToString(
        cryptoTransformSHA1.ComputeHash(buffer)).Replace("-", "");

    return hash;
}

// Original example without using directive or comments:
http://dotnetpulse.blogspot.com/2007/12/sha1-hash-calculation-in-c.html