Authenticating the identity of an authorized person

DETAILED DESCRIPTION The present invention seeks to provide a solution to the severe difficulties associated with card and other fraud.
According to the present invention there is provided a computer system for authenticating the identity of an authorised person, the computer system comprising: compare means operable to receive a first code comprising a plurality of characters in sequential positions identifying the authorised person and a second code comprising a plurality of characters in sequential positions obtained from an actual user and to compare the character of the first code with the characters of the second code to determine whether the second code is a corrupted version of the first code according to a predetermined corruption algorithm; and output means for producing an authentication signal if the first and second codes differ according to the predetermined corruption algorithm.
A method of authenticating an authorised person is also provided.
In one embodiment, the compare means compares each character of the second code with the character in the corresponding position of the first code to determine identity between the codes in all but a predetermined number of the character positions; and the output means produces an authentication signal if the characters of the first and second codes differ at only said predetermined number of the character positions or an invalid signal in other cases.
Preferably, the predetermined number is one - this makes the invention simple to implement yet effective against fraud.
Thus, according to a first embodiment of the present invention there is provided a computer system for authenticating the identity of an authorised person the computer system comprising: compare means for receiving a first code comprising a plurality of characters in sequential positions identifying the authorised person and a second code comprising a plurality of characters in sequential positions obtained from an actual user and for comparing each character of the second code with the character in the corresponding position of the first code to determine identiy between the codes in all but one of the character positions; and output means for producing an authentication signal if the characters of the first and second codes differ at only one of the character positions or an invalid signal in other cases