Andrew S Koenig

58128530, Sep 22, 1998

Apr 11, 1994

8/225880

Martin D. Carroll - Watchung NJ
Peter Juhl - Vestbjerg, DK
Andrew Richard Koenig - Gillette NJ

Lucent Technologies Inc. - Murray Hill NJ

G06F 945

395708

A method and apparatus for processing source code in a language processing system with improved parsing based on prefix analysis. A method in accordance with the present invention includes the steps of identifying a previously-parsed prefix of a source code translation unit; creating a parser in a parser state corresponding to the identified prefix; and parsing a remaining portion of the translation unit after the prefix using the parser in the parser state corresponding to the prefix. In one embodiment of the invention, the step of creating a parser includes retrieving stored level-one subtrees corresponding to the top-level statements in the prefix. The level-one subtrees corresponding to the prefix may be stored in the form of a prefix tree along with the text of the top-level source code statements represented by the prefix and a parser delta indicating the effect of the code statements on the parser state.

45904707, May 20, 1986

Jul 11, 1983

6/512887

Andrew R. Koenig - Elizabeth NJ

AT&T Bell Laboratories - Murray Hill NJ

H04Q 900
H04L 900
G06K 500

34082531

A system which employs a pair of encryption functions f and g in the "log on" protocol of a computer dial-up arrangement. The functions are inverses of each other and, hence, a random sequence when encrypted with f and then with g results in the original sequence. When a user wishes to "log on", the computer selects a random sequence and forms a challenge sequence. The user encrypts the challenge sequence with the function g and thus forms a response sequence. Encryption with the function f by the computer permits verification of the response sequence. The secrecy of the user's function is maintained by providing the user with an authenticating device having only two ports: a power port and an I/O port. The I/O port is connected to a microprocessor which accesses a memory that contains the secret encryption function g.