String clearKey = "test";
        IBuffer buffEntry = CryptographicBuffer.ConvertStringToBinary(clearKey, BinaryStringEncoding.Utf8);
        HashAlgorithmProvider algProvider = HashAlgorithmProvider.OpenAlgorithm(HashAlgorithmNames.Md5);

        IBuffer buffHashed = algProvider.HashData(buffEntry);

        byte[] bytesKey;
        CryptographicBuffer.CopyToByteArray(buffHashed, out bytesKey);
        Debug.WriteLine(String.Format("bytesKey lenght : {0}", bytesKey.Length));

string md5Hex = CryptographicBuffer.EncodeToHexStringbuffHashed(buffEntry);