US 6,286,105 B1 · Method for implementing link-level security to enforce access privileges

Abstract

A method and architecture for implementing link level security to enforce access privileges between a calling modem and an answering modem over a communication channel during a communication session in a modem employing a communication protocol capable of modulation modification. Security scramblers different from the standard scrambler inherent in the communication protocol are loaded into a calling modem and an answering modem. A password may alternatively be entered into the calling modem for verification prior to the enablement of the security process. During the training phase of the communication protocol, descriptors designating specific secure scramblers are passed from the calling modem to the answering modem for verification of the correct access privileges by the calling modem. The answering modem thereafter directs the calling modem to utilize yet another secure scrambler for the subsequent training and exchange of data. Since the secure scrambler modifies the modulation of each modem, incompatible scramblers are unable to properly train and therefore unable to establish a communication channel therebetween. An alternative implementation also employs scrambler hopping to provide yet further security.

Claims16

Dependent claims

In a modem employing a communication protocol capable of modulation modification utilizing a standard scrambler, a method of implementing link level security to enforce access privileges between a calling modem and an answering modem over a communication channel during a communication session, comprising the steps of:

a) exchanging at least one security scrambler descriptor from said calling modem to said answering modem, said descriptor uniquely identifying a security scrambler known to both said calling modem and said answering modem, said security scrambler differing from said standard scrambler;
b) verifying at said answering modem that said security scrambler designated by said at least one security scrambler descriptor from said calling modem was previously assigned to said calling modem;
c) training with said security scrambler said communication channel between said calling modem and said answering modem to optimize transmission parameters therebetween;
and
d) modifying said modulation of data using said security scrambler between said calling modem and said answering modem during a data transmission phase of said communication session, said modifying said modulation of data using said security scrambler step further comprises the step of hopping from said security scrambler to a second security scrambler also common to both said calling modem and said answering modem upon the occurrence of a predetermined condition.

2 more elements

A computer-readable medium for implementing link level security to enforce access privileges between a calling modem and an answering modem over a communication channel during a communication session, said computer-readable medium having computer executable instructions for performing the steps of:

a) exchanging at least one security scrambler descriptor from said calling modem to said answering modem, said descriptor uniquely identifying a security scrambler known to both said calling modem and said answering modem, said security scrambler differing from said standard scrambler;
b) verifying at said answering modem that said security scrambler designated by said at least one security scrambler descriptor from said calling modem was previously assigned to said calling modem;
c) training with said security scrambler said communication channel between said calling modem and said answering modem to optimize transmission parameters therebetween;
and
d) modifying said modulation of data using said security scrambler between said calling modem and said answering modem during a data transmission phase of said communication session, the step of modifying said modulation of data using said security scrambler further comprises computer executable instructions for performing the step of hopping from said security scrambler to a second security scrambler also common to both said calling modem and said answering modem upon the occurrence of a predetermined condition.

2 more elements

Dependencies are inferred from the claim text.

Method for implementing link-level security to enforce access privileges

Life of this patent

Method for implementing link-level security to enforce access privileges

Life of this patent

Abstract

Claims16