Generate a random(ish) token that is safe to be used in a URL. Allow caller to specify strength though number of generated random chars.

GenerateCryptographicallyStrongUrlSafeRandomToken.cs

// Bill Wilder | @codingoutloud | http://www.cloudarchitecturepatterns.com | Nov 2012
// Original: https://gist.github.com/4121999
// Similar GenerateUrlSafeRandomToken.cs, except upgraded to use crypto-strength RNG
// Add reference to System.Web.dll
public static string GenerateUrlSafeCryptographicallyStrongRandomToken(int strength = 16)
{
    using (var rng = new RNGCryptoServiceProvider())
    {
        var randomBytes = new byte[strength];
        rng.GetBytes(randomBytes);
        var token = HttpServerUtility.UrlTokenEncode(randomBytes); // unlike Base64, this is safe for use in URLs
        return token;
    }
}

GenerateUrlSafeRandomToken.cs

// Bill Wilder | @codingoutloud | http://www.cloudarchitecturepatterns.com | Nov 2012
// Original: https://gist.github.com/4121999

public static string GenerateUrlSafeRandomToken(int strength = 16)
{
   var random = new Random((int) DateTime.Now.Ticks);
   var randomBytes = random.NextBytes(new byte[strength]);
   var token = HttpServerUtility.UrlTokenEncode(randomBytes); // unlike Base64, this is safe for use in URLs
   return token;
}