Passive system for recovering cryptography keys
First Claim
1. A system for use in collecting and decrypting encrypted wireless signals in a wireless communications network (WCN), comprising:
- a first passive probe installed on a first interface and configured to monitor messaging possessing encryption keys;
a second passive probe, wherein the second passive probe comprises a wireless network monitor (WNM) configured to monitor transmissions between a WCN base station and a mobile device; and
a correlation processor operatively coupled to the first and second probes and configured to compare information received by each probe and to determine the encryption key as a result of the comparison, wherein the encryption key is useful to decrypt transmissions between the mobile device and the WCN base station;
wherein the correlation processor is configured to compare a challenge parameter and a challenge response parameter, and to find an encryption vector with the same challenge parameter and challenge response parameter, wherein the encryption vector contains the challenge parameter, the challenge response parameter and the encryption key for the mobile device.
2 Assignments
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Accused Products
Abstract
Modern cellular wireless communications providers strive to keep their network and subscribers secure through various means. The identity of the subscriber may be obfuscated through the use of a temporary identifier for most network transactions including signaling events, voice calls, SMS messages and data sessions. A subscriber'"'"'s unique identity may only be transmitted over the air in an encrypted form. Similarly, the content of voice calls, SMS messages and data sessions may also be encrypted when transmitted over the air and even when transferred over internal network interfaces. However, the use of encryption presents significant challenges for law enforcement communities when court ordered lawful intercept is required to monitor and locate subscribers utilizing the wireless networks for illegal and/or terrorist purposes. A technique to aid in the determination of a subscriber'"'"'s unique wireless identity and the decryption of encrypted signals would be very useful for lawful intercept. In this document we describe an architecture and technique to aid in the decryption of encrypted wireless signals for lawful intercept by determining the current encryption key. It may also be used to decrypt encrypted signals on internal interfaces of the wireless and wireline networks.
16 Citations
16 Claims
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1. A system for use in collecting and decrypting encrypted wireless signals in a wireless communications network (WCN), comprising:
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a first passive probe installed on a first interface and configured to monitor messaging possessing encryption keys; a second passive probe, wherein the second passive probe comprises a wireless network monitor (WNM) configured to monitor transmissions between a WCN base station and a mobile device; and a correlation processor operatively coupled to the first and second probes and configured to compare information received by each probe and to determine the encryption key as a result of the comparison, wherein the encryption key is useful to decrypt transmissions between the mobile device and the WCN base station; wherein the correlation processor is configured to compare a challenge parameter and a challenge response parameter, and to find an encryption vector with the same challenge parameter and challenge response parameter, wherein the encryption vector contains the challenge parameter, the challenge response parameter and the encryption key for the mobile device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification