Patent ID: 8009826
Filing Date: 2011-08-30
Classification: H04L,H04W

Abstract:
1. A system for decrypting an encrypted cellular signal comprising: a transmitter configured to impersonate a first party to a cellular communication; first processing circuitry functionally associated with said transmitter, configured to request from a second party to said communication, via said transmitter, to send a first ciphertext encrypted using a first cellular encryption method; a receiver configured to receive said first ciphertext; and second processing circuitry being functionally associated with said receiver, configured to recover an encryption key used to encrypt said first ciphertext by cryptanalyzing said first ciphertext, wherein said cryptanalyzing includes deriving equations over the key-stream output of the first cellular encryption method by either: (1) XORing together bits of said first ciphertext based on an error correction coding scheme; or (2) XORing bits of said first ciphertext with bits which are an output of an error correction coding scheme; or (3) both; and wherein, said second processing circuitry is further configured to use said recovered encryption key to decrypt or produce a second ciphertext encrypted using a second cellular encryption method.