US 5,978,475 A · Event auditing system

Abstract

In many computer applications, sensitive information must be kept on an untrusted machine. Such information must be protected against attackers, as well as against partially trusted entities to be given partial, but not total, access to the stored information. This invention provides a method, apparatus and computer-readable data structure for inhibiting an attacker from accessing or corrupting information stored by an untrusted machine. More specifically, in a log file generated during a process in which the untrusted machine is in limited communication with a trusted machine, entries generated prior to the attack remain secure (they cannot be modified without detection), even though subsequent entries can not be trusted. One embodiment of the invention also allows a partially trusted verifier to read and verify entries in the log file, but not to change them without detection. In another embodiment of the invention, operating with or without the trusted machine, the untrusted machine's log file can also incorporate log files of other processes.

Claims70

Dependent claims

A method for creating an audit log entry having enhanced security against tampering, comprising the steps of:

(a) receiving a quantity to be logged;
(b) concatenating said quantity with at least a portion of a verification chain entry for a preceding entry;
(c) using an entry-specific cryptographic key having been derived by computing a cryptographic hash on at least a cryptographic key for a preceding entry, performing a verifiable cryptographic operation on the result of step (b) to generate a current verification chain entry;
and
(d) writing, to a memory, an audit log entry including said quantity and said generated verification chain entry.

2 more elements

Dependencies are inferred from the claim text.

Event auditing system

Life of this patent

Event auditing system

Life of this patent

Abstract

Claims70