Base58 Encode

base58.cs

using System;
using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace UnitTestProject1
{
    [TestClass]
    public class UnitTest1
    {
        [TestMethod]
        public void ShouldEncodeIntegerToBase58()
        {
            int numberToEncode = 299542347;
            Assert.AreEqual("steve", Encode(numberToEncode));
        }

        [TestMethod]
        public void ShouldDecodeBase58ToInteger()
        {
            string stringToDecode = "steve";
            Assert.AreEqual(299542347, Decode(stringToDecode));
        }

        
        //Ported from https://www.flickr.com/groups/api/discuss/72157616713786392/
        public string Encode(int num)
        {
            string alphabet = "123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";
            int baseCount = alphabet.Length;
            string encoded = "";
            while (num > 0)
            {               
                int remainder = num % baseCount;
                num = Convert.ToInt32(num / baseCount);
                encoded = alphabet[remainder].ToString() + encoded;
            }
            return encoded;
        }

        private int Decode(string stringToDecode)
        {
            string alphabet = "123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";
            int decoded = 0;
            int multi = 1;

            while (stringToDecode.Length > 0)
            {
                string digit = stringToDecode.Substring(stringToDecode.Length - 1);
                decoded = decoded + (multi * alphabet.IndexOf(digit));
                multi = multi * alphabet.Length;
                stringToDecode = stringToDecode.Substring(0, stringToDecode.Length - 1);
            }

            return decoded;
        }
    }
}