TEMPORAL PROXIMITY TO VERIFY PHYSICAL PROXIMITY

• US 20090003605A1
• Filed: 09/10/2008
• Published: 01/01/2009
• Est. Priority Date: 06/28/2001
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: EPSTEIN, MICHAEL
• Granted Patent: US 8,107,627 B2
• Time in Patent Office: Days
• US Class Current: 380/258
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/554 involving event detection and direct action
• CPC Class Codes: G06F 2221/2111 Location-sensitive, e.g. geographical location, GPS
• CPC Class Codes: H04L 63/0492 by using a location-limited connection, e.g. near-field communication or limited proximity of entities
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 9/3271 using challenge-response

Abstract

A security system assesses the response time to requests for information to determine whether the responding system is in physical proximity to the requesting system. Generally, physical proximity corresponds to temporal proximity. If the response time indicates a substantial or abnormal lag between request and response, the system assumes that the lag is caused by the request and response having to travel a substantial or abnormal physical distance, or caused by the request being processed to generate a response, rather than being answered by an existing response in the physical possession of a user. If a substantial or abnormal lag is detected, the system is configured to limit subsequent access to protected material by the current user, and/or to notify security personnel of the abnormal response lag.

Claims

1-13. -13. (canceled)

14. A security system comprising:

a processor (120) and an access device (132) configured to execute a challenge-response protocol between them, during which protocol a secret key is exchanged;

a timer (128) configured to measure a lag between a response to a challenge sent during said protocol; and

a verifier (126) configured to cause the protocol to be aborted if the measure lag differs substantially from an expected response time.

15. The security system as claimed in claim 14, wherein

the difference is correlated to a physical proximity between a first source of the one or more requests and a second source of the one or more responses.

16. The security system as claimed in claim 14, wherein

the assessment of the response times forms an assessment of whether the one or more responses were communicated via a network connection.