Simple encryption rijndael encryption wrapper

EncryptionService

/// <summary>
    /// Adapted from:
    /// http://www.codeproject.com/Articles/5719/Simple-encrypting-and-decrypting-data-in-C
    /// </summary>
    public class EncryptionService : IEncryptionService
    {
        private readonly string _password;
        private readonly byte[] _salt;

        public EncryptionService( string password, string salt )
        {
            _password = password;
            _salt = new ASCIIEncoding().GetBytes(salt);
        }

        public SymmetricAlgorithm NewRijndael()
        {
            var alg = Rijndael.Create( );
            var key = new Rfc2898DeriveBytes( _password, _salt, 999 );
            alg.IV = key.GetBytes( alg.BlockSize / 8 );
            alg.Key = key.GetBytes( alg.KeySize / 8 );
            return alg;
        }

        public string Encrypt( string clearText )
        {
            return Convert.ToBase64String(
                Encrypt(
                    Encoding.Unicode.GetBytes(
                        clearText
                        )
                    )
                );
        }

        public byte[ ] Encrypt( byte[ ] clearData )
        {
            using(var ms = new MemoryStream( ))
            using (var cs = new CryptoStream(ms, NewRijndael().CreateEncryptor(), CryptoStreamMode.Write))
            {
                cs.Write( clearData, 0, clearData.Length );
                cs.Close();
                return ms.ToArray( );
            }
        }

        public string Decrypt( string cipherText )
        {
            return Encoding.Unicode.GetString(
                Decrypt(
                    Convert.FromBase64String(
                        cipherText
                        )
                    )
                );
        }

        public byte[ ] Decrypt( byte[ ] cipherData )
        {
            using ( var ms = new MemoryStream( ) )
            using ( var cs = new CryptoStream(ms, NewRijndael().CreateDecryptor(), CryptoStreamMode.Write) )
            {
                cs.Write( cipherData, 0, cipherData.Length );
                cs.Close( );
                return ms.ToArray( );
            }
        }       
    }

    public interface IEncryptionService
    {
        SymmetricAlgorithm NewRijndael();
        string Encrypt( string clearText );
        byte[ ] Encrypt( byte[ ] clearData );
        string Decrypt( string cipherText );
        byte[ ] Decrypt( byte[ ] cipherData );
    }