Searches a bigger array of bytes for a tinyer array of bytes

ByteComparison.cs

public class Byte
    {
        /// <summary>
        /// Gets the starting pointers in array of the given element
        /// </summary>
        /// <param name="array">Bigger element where is searched in</param>
        /// <param name="element">Tiny pattern which has to be matched in <see cref="array"/></param>
        /// <returns></returns>
        public static List<int> GetOccurancePtrs(byte[] array, byte[] element)
        {
            var firstMatchPtrs = new List<int>();
            var secondMatchPtrs = new List<int>();
            int ihalp1 = array.Length - element.Length;

            //Mark each and every position in the array where the first element matches
            for (int i = 0; i < ihalp1; i++)
            {
                if (array[i] == element[0])
                    firstMatchPtrs.Add(i);
            }

            //Start the "Deep scan" by looking at the first pointer collection
            for (int i = firstMatchPtrs.Count - 1; i >= 0; i--)
            {
                if (IsMatch(array, element, firstMatchPtrs[i]))
                    secondMatchPtrs.Add(firstMatchPtrs[i]);
            }
            return secondMatchPtrs;
        }

        private static bool IsMatch(byte[] array, byte[] element, int pointer)
        {
            //return false wenn pointer+element.lengh>ARRAY
            if ((element.Length + pointer) > array.Length)
            {
                return false;
            }
            int ihalp2 = element.Length - 1;
            for (int i = 0; i < ihalp2; i++)
            {
                if (array[i + pointer] != element[i])
                    return false;
            }
            return true;
        }
    }