Abstract: A user-authentication system includes an authorized user device (AUD) for transmission of dtmf tones to a user-verification system (UVS) over a telephone network, where user-verification is performed and authorized users are granted access to a desired service. In a memory module of the AUD, a plurality of passphrases and identifying data are stored for subsequent transmission to the UVS. The compensating system comprises a pair of tone devices that generate low frequency tones and high frequency tones, respective that are amplified to different amplification levels. The amplification levels compensate for the low and high frequency tone transmission characteristics associated with different microphones in use in a public telephone system. The systems further performs channel normalization with the user-activated AUD and the UVS. Tone signals representative of the access telephone number transmitted by the AUD to reach the UVS, have a reference amplitude of zero.

Abstract: A user-authentication system includes an authorized user device (AUD) for transmission of DTMF tones to a user-verification system (UVS) over a telephone network, where user-verification is performed and authorized users are granted access to a desired service. In a memory module of the AUD, a plurality of passphrases and identifying data are stored for subsequent transmission to the UVS. The UVS includes a memory module for receiving and storing the passphrases and identifying data, and a processor for determining whether user-stated passphrases correspond to the stored passphrases, and for prompting the user with knowledge-based questions and determining whether the identifying data corresponds to answers given by a user in response to the knowledge-based questions.

Abstract: A user-authentication system includes an authorized user device (AUD) for transmission of dtmf tones to a user-verification system (UVS) over a telephone network, where user-verification is performed and authorized users are granted access to a desired service. In a memory module of the AUD, a plurality of passphrases and identifying data are stored for subsequent transmission to the UVS. The UVS includes a memory module for receiving and storing the passphrases and identifying data, and a processor for determining whether user-stated passphrases correspond to the stored passphrases, and for prompting the user with knowledge-based questions and determining whether the identifying data corresponds to answers given by a user in response to the knowledge-based questions.

Abstract: An information storage device for storing and outputting personal identification information. The storage device includes memory and a controller. The memory stores personal identification information and memory access control information. The memory access control information includes a first set of tones. The controller includes an input device, an output device, and a microprocessor. The microprocessor causes the output device to output the stored personal identification information in response to the input device receiving a series of tones corresponding to the first set of tones of the memory access control information. The personal identification information can include biometric identification information. In one embodiment, a security system utilizes a plurality of information storage devices for controlling unauthorized access to a resource.

Abstract: An auto-dialer suitable for use as a smart card capable of being acoustically coupled to a telephone and being reprogrammed in response to acoustic signals. The programming and other features of the auto-dialer can be enabled or disabled by the auto-dialer in response to persecuted signals, e.g., a string of DTMF tones. Encryption of calling card and other data into destination telephone numbers is achieved by selectively altering persecuted characteristics of a DTMF tone sequence, such as the duration of tones, the period of silence between tones and the twist between Lo-band and Hi-band tones of DTMF tone pairs in a DTMF tone sequence representing a telephone number. The encryption of data into the telephone number does not affect the ability of standard telephone switching circuitry to recognize the destination number.

Abstract: A system and method using personal identification numbers and associated prompts for controlling unauthorized use of a security device and unauthorized access to a resource. The method includes requesting an authorized user of a security device to select a set of N PINs and N distinct phrases, each one of the N distinct phrases being associated with a corresponding one of the N PINs for acting as a prompt to remind the user of the corresponding one of the N PINs. A current user of the security device is prompted using one of the N distinct phrases and the user's response to the prompt is compared to the associated PIN to determine whether the current user of the security device is the authorized user. The current user is granted access to the resource or is granted use of the security device if it is determined that the current user of the security device is the authorized user.

Abstract: A system and method for selecting and generating telephone access numbers for limiting access to a telephone service. The system includes an auto-dialer having a system clock, a memory device, a processor, and a tone generator. The auto-dialer is used to transmit user-associated data to a telephone service. The system clock generates a system time and the memory device stores data and a plurality of telephone numbers, each of which is capable of accessing the telephone service at different times. The processor is electrically coupled to the system clock and to the memory device and can select the telephone number capable of accessing the telephone service at any moment in time as a function of the system time. The auto-dialer can also include a number generator operating according to a preselected pseudo random sequence, in electrical communication with the system clock and the processor, where the output of the system clock is used as a seed number to the number generator.