Scientific-atlanta, Inc.

Global Crypto Systems

Todd A Merrill

Scott E Hrastar

Roy A Bowcutt

Mark E Schutte

David A Sedacca

James E Barker

Various systems, methods, and programs embodied in computer-readable mediums are provided for digital authentication using digitally signed images. In one representative embodiment, a method includes extracting a first image portion from an image selected by a first party, where the first image portion including a first encoded part of an second party digital signature, and obtaining a second image portion associated with the first image portion, where the second image portion including a second encoded part of the second party digital signature. The first and second encoded parts of the second party digital signature are decoded and validity of the second party digital signature is confirmed based upon a second party public key.

Methods and systems for digital authentication using digitally signed images

An asymmetrical network is disclosed for coupling customer-premises Internet hosts such as personal computers to the Internet. The head end of a CATV system has a high-bandwidth connection to the Internet. The CATV system supports a plurality of concurrent channels to which an RF modem is capable of tuning. The RE modem is capable of receiving information from the head end that specifies the channel to which the RF modem should tune. Once tuned to the specified channel, the RF modem is capable of utilizing the CATV system for carrying high-speed data traffic. The high-speed data traffic can support Internet access using the Internet Protocol (IP).

Router for use with a link that has a set of concurrent channels

An asymmetrical network for coupling customer-premises Internet hosts such as personal computers to the Internet. The head end of a CATV system has a high-bandwidth connection to the Internet. The down link connecting the personal computers to the Internet is the cables provided by the CATV system; the up link is a telephone connection to the head end. A router is connected to the down link by means of an RF modem, to the up link by means of an analog modem, and to a LAN which is connected to the Pcs. The router routes IP packets for the hosts that are received on the CATV cable to the hosts via the LAN; it routes IP packets from the hosts that are destined for the Internet to the head end via the telephone line. The asymmetrical network conserves IP addresses and addresses on the CATV cable by dynamically allocating the IP addresses for an RF modem's hosts and an address on the CATV cable for the RF modem in response to a request made by the RF modem via the telephone line. It further saves IP addresses by assigning a non-unique IP address to the router for use inside the LAN. When the CATV system fails, the asymmetrical network automatically begins to use the telephone line as both the up link and the down link, and when the CATV system is restored, the asymmetrical network automatically returns to using the CATV cable as the down link and the telephone line as the up link. A further feature of the asymmetrical network is that the head end components and the RF modem have IP addresses, so that standard TCP/IP protocols can be used to control the asymmetrical network.

The preferred embodiment of the present invention is a cable modem apparatus for reliably providing a personal computer access to the Internet through a cable television link and a public switched telephone network link. The invention includes: a cable television link failure detector connected to the cable television link; a message generator connected to the cable television link failure detector, where the message generator is configured to generate at least one message responsive to the cable television link failure detector; and a message transmitter connected to the message generator, where the message transmitter is configured to transmit the at least one message through the public switched telephone network link to cause Internet communications to be communicated to the personal computer through the public switch telephone network link.

Method of using routing protocols to reroute packets during a link failure

Apparatus and methods for automatically rerouting packets in the event of a link failure

A method for transporting digital data from a sender to a receiver in a system where the digital data is broken into data packets for transmission over radio frequency channels, each data packet including forward error-correcting code, the method comprising the steps of receiving the data packets at the receiver; reconstructing the data packets to the digital data, the forward error-correcting code for fixing corrupted data packets; and halting the data packet reconstructing step if a data packet is uncorrectable.

Growing community of inventors

Alpharetta, GA, United States of America

Todd A Merrill