Patent Number: 6,298,360

Title: Method and apparatus for generating a highly random number while using existing circuitry

Abstract: A random number generator, useful in association with a computer system of a computer network, generates a randomly distributed back-off time interval between a collision and the retransmission of the packet, e.g. for Ethernet's collision sense multiple access/collision detect (CSMA/CD) protocol. The random number generator includes a data-based number generator, a timer-based number generator and a number combiner. The combiner is provided the output numbers from data-based and timer-based number generators, and in turn generates a random number. A user selectable initialization number is provided as a seed number for the data-based number generator. Subsequently, a cyclic redundency check (CRC) generator provides numbers for data-based number generator. A free-running timer provides numbers for the timer-based number generator. The user selectable initialization number is also provided as a seed number for the data-based and timer-base generators. Subsequently, the same initialization number or a different number can be loaded into data-base number generator. A feedback path is provided between the output node of the data-based number generator and an adder of the data-based number generator. In this embodiment, the number combiner includes an exclusive "OR" circuit. Advantages of the present invention include a simple digital-only circuit that is easy to fabricate. In addition, the random number generator leverages off existing networking circuitry, e.g., the CRC generator.

Inventors: Muller; Shimon (Sunnyvale, CA)

Assignee: Sun Microsystems, Inc.

International Classification: G06F 7/58 (20060101); G06F 007/58 ()

Expiration Date: 10/02/2018