1. A method of matching signature string patterns, comprising: dividing a payload of introduction traffic into character columns, wherein the payload of introduction traffic is divided such that a character column to be searched is the same size as a signature substring character column of a signature string pattern that is tokenized into signature substrings, the signature string pattern being stored in a signature matching engine; determining whether there exists a previous character column of the divided payload, which was compared to the signature string pattern before the character column to be searched, that was matched to a signature substring of the signature string pattern; when the previous character column matching a signature substring of the signature string pattern does not exist, calling a memory table of an internal memory block address corresponding to a hash value of the character column to be searched; determining whether the character column to be searched is matched to a signature substring stored in the called memory table; stopping a matching process when the signature substring stored in the called memory table is not matched to the character column to be searched; analyzing whether the signature substring is a last substring in the signature substrings of the signature string pattern when the signature substring stored in the called memory table is matched to the character column to be searched; generating an alarm when the signature substring matched to the character column to be searched is the last substring of the signature string pattern; and analyzing whether a next character column to be searched is matched to a substring stored in an external memory block address when the external memory block address is called from the called memory table and the signature substring matched to the character column to be searched is not the last substring of the signature substring pattern.