# US 8,571,188 B2 · Method and device for secure phone banking > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,571,188 B2 - Document ID: US8571188B2 - Status: Granted - Kind: B2 - Application number: 11/611,825 - Filed: 2006-12-15 - Published: 2008-06-19 - Granted: 2013-10-29 - Earliest claimed: 2006-12-15 - Assignees: QUALCOMM Incorporated - Applicants: Alexander Gantman; Gregory G. Rose; Jae-Hee Choi; John W. Noerenberg, II - Inventors: Alexander Gantman; Gregory G. Rose; Jae-Hee Choi; John W. Noerenberg, II - Web page: https://patentgrep.com/patent/US8571188B2 ## CPC - H04L 9/00: {Cryptographic mechanisms or cryptographic} arrangements for secret or secure communications; Network security protocols - H04M 1/68: Circuit arrangements for preventing eavesdropping - H04M 3/16: with lock-out or secrecy provision in party-line systems - H04M 11/00: Telephonic communication systems specially adapted for combination with other electrical systems - H04M 1/505: {signals generated in digital form} - H04M 2203/609: Secret communication - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08) ## Abstract A small form-factor security device is provided that may be inserted in series with a telephone line to encrypt dual tone multi-frequency (DTMF) tones from a telephone to prevent unauthorized disclosure of sensitive information. A receiving device decrypts the encrypted DTMF tones to receive the original information sent by the telephone. The security device acts as a second factor in a two-factor authentication scheme with a tele-services security server that authenticates the security device. ## Claims ### Claim 1 A method operational on a mobile communication device, comprising: initiating a call to a tele-services station, wherein an authentication key has been pre-arranged between the mobile communication device and the tele-services station; receiving a pseudorandom authentication challenge from the tele-services station in response to initiating the call; sending an authentication response to the tele-services station, wherein the authentication response is a function of the pseudorandom authentication challenge and the authentication key; requesting sensitive information from the tele-services station; and receiving the requested sensitive information from the tele-services station if the authentication response is accepted by the tele-services station. ### Claim 2 (depends on 1) The method of claim 1 further comprising: sending a user identifier to the tele-services station, wherein the user identifier is further used to authenticate the mobile communication device. ### Claim 3 (depends on 1) The method of claim 1 wherein the mobile communication device is a mobile phone and the tele-services station is associated with a financial institution. ### Claim 4 (depends on 1) The method of claim 1 further comprising: generating a session key based on the pseudorandom authentication challenge and the authentication response; and decrypting the sensitive information using the session key. ### Claim 5 (depends on 1) The method of claim 1, wherein the sensitive information is received as a plurality of dual tone multi-frequency (DTMF) tones. ### Claim 6 (depends on 5) The method of claim 5, further comprising: decrypting the received DTMF tones to obtain the sensitive information. ### Claim 7 (depends on 6) The method of claim 6, wherein decrypting the received DTMF tones includes converting a first DTMF tone into a first symbol by selecting a first translation table from a plurality of translation tables based on the pseudorandom authentication challenge and the authentication key; translating the first DTMF tone into a first symbol using the selected first translation table; converting a second DTMF tone into a second symbol by selecting a second translation table from the plurality of translation tables based on the pseudorandom authentication challenge and the authentication key; and translating the second DTMF tone into a second symbol using the selected second translation table. ### Claim 8 (depends on 7) The method of claim 7, wherein the second translation table is obtained by shuffling symbols in the first translation table. ### Claim 9 (depends on 1) The method of claim 1, further comprising: transmitting sensitive information to the tele-services station by encrypting the transmitted sensitive information a plurality of dual tone multi-frequency (DTMF) tones. ### Claim 10 (depends on 9) The method of claim 9, wherein encrypting the plurality of DTMF tones includes selecting a first translation table from a plurality of translation tables based on the pseudorandom authentication challenge and the authentication key; converting a first symbol into a first DTMF tone using the selected first translation table; selecting a second translation table from the plurality of translation tables based on the pseudorandom authentication challenge and the authentication key; converting a second symbol into a second DTMF using the selected second translation table. ### Claim 11 A mobile communication device, comprising: means for initiating a call to a tele-services station, wherein an authentication key has been pre-arranged between the mobile communication device and the tele-services station; means for receiving a pseudorandom authentication challenge from the tele-services station in response to initiating the call; means for sending an authentication response to the tele-services station, wherein the authentication response is a function of the pseudorandom authentication challenge and the-authentication key; means for requesting sensitive information from the tele-services station; and means for receiving the requested sensitive information from the tele-services station if the authentication response is accepted by the tele-services station. ### Claim 12 (depends on 11) The device of claim 11 further comprising: means for sending a user identifier to the tele-services station, wherein the user identifier is further used to authenticate the mobile communication device. ### Claim 13 (depends on 11) The device of claim 11 further comprising: means for generating a session key based on the pseudorandom authentication challenge and the authentication response; and means for decrypting the sensitive information using the session key. ### Claim 14 A mobile communication device, comprising: a communication module for communicating over a wireless communication network; and a processing circuit coupled to the communication module, the processing circuit configured to initiate a call to a tele-services station, wherein an authentication key has been pre-arranged between the mobile communication device and the tele-services station; receive a pseudorandom authentication challenge from the tele-services station in response to initiating the call; send an authentication response to the tele-services station, wherein the authentication response is a function of the pseudorandom authentication challenge and the-authentication key; request sensitive information from the tele-services station; and receive the requested sensitive information from the tele-services station if the authentication response is accepted by the tele-services station. ### Claim 15 (depends on 14) The device of claim 14 wherein the processing circuit is further configured to generate a session key based on the pseudorandom authentication challenge and the authentication response; and decrypt the sensitive information using the session key. ### Claim 16 A non-transitory machine-readable medium having one or more instructions operational on a security device for securing information transmitted by a telephone, which when executed by a processor causes the processor to: initiate a call to a tele-services station, wherein an authentication key has been pre-arranged between the mobile communication device and the tele-services station; receive a pseudorandom authentication challenge from the tele-services station in response to initiating the call; send an authentication response to the tele-services station, wherein the authentication response is a function of the pseudorandom authentication challenge and the-authentication key; request sensitive information from the tele-services station; and receive the requested sensitive information from the tele-services station if the authentication response is accepted by the tele-services station. ### Claim 17 (depends on 16) The non-transitory machine-readable medium of claim 16 having one or more instructions which when executed by a processor causes the processor to further: generate a session key based on the pseudorandom authentication challenge and the authentication response; and decrypt the sensitive information using the session key.