Fibonacci Encoder/Decoder

gistfile1.cs

//
// Original Author: Software Assassin
//
// GNU All-Permissive License:
// Copying and distribution of this file, with or without modification,
// are permitted in any medium without royalty provided the copyright
// notice and this notice are preserved. This file is offered as-is,
// without any warranty.
//

using System;
using System.Text;
using System.Collections.Generic;

namespace Assassin
{
	public static class Fibonacci
	{
		public static string Decode(string input)
		{
			StringBuilder retval = new StringBuilder();

			int left = (int)input.Substring(0, 1)[0];
			int right = (int)input.Substring(input.Length - 1)[0];
			int together = System.Convert.ToInt32(String.Format("{0}{1}"
				, (left - 32).ToString()
				, (right - 32).ToString()
				));

			int[] fibonacciVals = Fibonacci.GetFibonacciValues(together);
			for (int i = 0; i < together; i++)
			{
				int pad = i + 5;
				retval.Append(input.Substring(fibonacciVals[pad] + 1, 1));
			}

			return retval.ToString();
		}
		public static string Encode(string input)
		{
			StringBuilder retval = new StringBuilder();

			//get info
			int length = input.Length;

			//cache finobacci sequence
			int[] fibonacciVals = Fibonacci.GetFibonacciValues(length);

			//generate hashed value
			Random r = new Random();

			retval.Append(char.ConvertFromUtf32((length / 10) + 32));
			retval.Append(char.ConvertFromUtf32(r.Next(32, 127)));
			retval.Append(char.ConvertFromUtf32(r.Next(32, 127)));
			retval.Append(char.ConvertFromUtf32(r.Next(32, 127)));
			retval.Append(char.ConvertFromUtf32(r.Next(32, 127)));

			for (int i = 0; i < length; i++)
			{
				int pad = i + 5;
				retval.Append(input.Substring(i, 1));
				for (int j = fibonacciVals[pad] + 1; j <= fibonacciVals[pad + 1] - 1; j++)
					retval.Append(char.ConvertFromUtf32(r.Next(32, 127)));
			}

			retval.Append(char.ConvertFromUtf32((length % 10) + 32));

			return retval.ToString();
		}

		//helper methods
		public static int[] GetFibonacciValues(int length)
		{
			int colLength = length + 7;
			int[] fibonacciVals = new int[colLength];

			for (int i = 0; i < 3; i++)
				fibonacciVals[i] = Fibonacci.fib(i);
			for (int i = 3; i < colLength; i++)
				fibonacciVals[i] = fibonacciVals[i - 1] + fibonacciVals[i - 2];

			return fibonacciVals;
		}
		public static int fib(int num)
		{
			if (num <= 1)
				return num;
			else
				return fib(num - 1) + fib(num - 2);
		}

	}
}

Use static Encode/Decode methods to parse strings. Class uses Fibonacci sequence to render strings unreadable to human eye.