Remote keyless entry user-transparent auto...

Communications: electrical – Continuously variable indicating – With meter reading

Utility Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C370S389000, C375S354000, C340S870030

Utility Patent

active

06169492

ABSTRACT:

FIELD OF THE INVENTION
This invention is related to the field of remote keyless entry systems for use in vehicular applications and more particularly to an authentication system with a user-transparent auto re-synchronization apparatus and method.
BACKGROUND OF THE INVENTION
Contemporary vehicle's often employ Remote Keyless Entry (R.K.E.) systems that include control functions such as those to unlock doors of the vehicle, start the engine in the vehicle, or to open a garage door. Typically radio signals are transmitted from an R.K.E. transmitter which is typically a portable device, to an R.K.E. receiver which is typically mounted in a vehicle or in a garage. When the radio signals are transmitted, it is feasible, using electronic eavesdropping, to record the radio signals for later re-transmission to operate the control functions of the vehicle or the garage door opener.
To dissuade unauthorized access, R.K.E. systems are made more secure by digitally encoding the radio signals transmitted between the R.K.E. transmitter and the R.K.E. receiver. Before the digitally encoded radio signals received by the R.K.E. receiver can be used, their origin needs to be validated. This validation process is often called authentication.
One protection mechanism built into many R.K.E. authentication systems is a device or procedure called a rolling counter. Typically, when a control function, such as “unlock doors of the vehicle” is selected by the user by depressing an associated key on an R.K.E. keypad, an R.K.E. transmitter-side counter is incremented. The symbolic count of this R.K.E. transmitter-side counter is encoded along with the “unlock doors of the vehicle” command and various other data and transmitted to the R.K.E. receiver. The R.K.E. receiver then decodes the various data including the symbolic count of the R.K.E. transmitter-side counter which is compared with a symbolic count of an R.K.E. receiver-side counter. Sometimes this is called a challenge-count. If the symbolic count of the R.K.E. transmitter-side counter matches the symbolic count of the R.K.E. receiver-side counter, then the user command is authenticated and the R.K.E. receiver unlocks the doors of the vehicle. A match is typically considered to be an incremental symbolic value within a range of the R.K.E. receiver-side counter. For example, if the R.K.E. receiver-side counter is 1,983 counts, indicating that 1,983 R.K.E. authentic transmissions have been received, and the received symbolic count of the R.K.E. transmitter-side counter is 1,984 counts, a match is implied. If the received symbolic count of the R.K.E. transmitter-side counter is 1,990, then a match has occurred because the received symbolic count was about the same as the receiver-side counter but also greater than the receiver-side counter. Some systems look for a unit incremental count, and some systems allow a range of incremental counts—such as a range of 256 counts. Provision of this range anticipates that the user may inadvertently press a key of the R.K.E. keypad, incrementing the symbolic count of the R.K.E. transmitter-side counter. The range is kept to a relatively small value such as 256 counts to discourage massive replay attacks.
Sometimes a user can inadvertently increment the transmitter-side counter beyond the range. When this happens the R.K.E. system needs to be re-synchronized. While various authentication methods and systems exist they are inadequate because they lack an efficient approach for re-synchronizing the R.K.E. system without requiring any specific action on the user's part while maintaining the existing cryptographic robustness against various attacks. Some schemes require a specific user re-synchronization sequence. Users have to go find a manual to know what that sequence is. Imagine trying to get into your car and finding out you have to go find a manual.
What is needed is an improved approach that will automatically re-synchronize an R.K.E. receiving unit to one of its corresponding transmitting units in a manner that is totally transparent to the user and preserves the existing cryptographic strength of the system.


REFERENCES:
patent: 4847614 (1989-07-01), Keller
patent: 5852944 (1998-12-01), Collard, Jr. et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Remote keyless entry user-transparent auto... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Remote keyless entry user-transparent auto..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Remote keyless entry user-transparent auto... will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2458612

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.