C#

private static byte[] StringToByteEntryId(String strEntryId){
	byte[] entryId = new byte[strEntryId.Length/2];
	
	String strByte;
	int byteIndex = 0;
	for(int n=0; n<strEntryId.Length; n+=2){
		strByte = strEntryId.Substring(n, 2);
		entryId[byteIndex] = Convert.ToByte(strByte, 16);
		byteIndex++;
	}
	
	return entryId;

private static String ByteToStringEntryId(byte[] bytes) {
	StringBuilder result = new StringBuilder(bytes.Length*2);
	String currentNumber;
			
	foreach(byte b in bytes) {
		currentNumber = b.ToString("X2");
		result.Append(currentNumber);
	}

	String entryId = result.ToString();
	return entryId;
}