| 5392357 |
Secure telecommunications |
| Feb-21-1995 |
A security node disposed in the telecommunications network connecting calling and called parties transforms information (which can be voice, data, facsimile, video and other types of calls or messages)... |
| 5365590 |
System for providing access to digitally encoded communications in a distributed switching network |
| Nov-15-1994 |
A distributed switching network (switch) routes audio and control signals throughout the switch from various audio sources to one or more audio destinations. Audio sources such as mobile/portable radio... |
| 5301246 |
Data communications equipment security device using calling party directory number |
| Apr-5-1994 |
A secure method of accessing a computer facility is provided within the data communications equipment (DCE), e.g., a modem or a terminal server, by the use of Calling Party Directory Number (CPDN). In... |
| 5301234 |
Radiotelephone installation for prepayment operation with security protection |
| Apr-5-1994 |
In the course of the intercommunication between the base station and the autonomous telephone set, the first means of authentication initially generates a keyword dependent on the call charge for the current... |
| 5289542 |
Caller identification system with encryption |
| Feb-22-1994 |
Telephone call identification service that safeguards the privacy of an originating station (calling party), while providing useful identifying information to a destination station (called party), is achieved... |
| 5280529 |
Communication network intended for secure transmissions |
| Jan-18-1994 |
A secure communications network having different types of subscriber terminals (1-4) and switching modules (7-8) connected to other switching modules in the network includes cryptographic devices (13-15)... |
| 5210794 |
Apparatus and method for establishing crypto conferences on a telecommunications network |
| May-11-1993 |
A method to establish a speech conference connection between a group of conference participating nodes (2,4,8) which can freely be selected among a greater plurality of nodes (2-9) having conference facilities,... |
| 5181243 |
System and method for communications security protection |
| Jan-19-1993 |
A system and method are disclosed for preventing intelligible interception of information signals transmitted over a two-direction line. A masking signal is applied through a hybrid circuit at the receiving... |
| 5168519 |
System and method for securing DTMF transmission |
| Dec-1-1992 |
A technique for inhibiting intelligible interception of information signals transmitted over a line from a first site to a second site. A masking signal is applied to the line immediately upon the detection... |
| 5148478 |
System and method for communications security protection |
| Sep-15-1992 |
A system and method are disclosed for preventing intelligible interception of information signals transmitted over a two-direction line. A masking signal is applied through a hybrid circuit at the receiving... |
| 5136648 |
Message storage security system |
| Aug-4-1992 |
A voice message system having a plurality of user voice mailboxes is disclosed. The voice message system utilizes a method in which a message is encrypted using a unique encrypting key corresponding to... |
| 5115466 |
Communication network intended for secure transmission of speech and data |
| May-19-1992 |
This invention relates to a communication network intended for secure transmission of speech and data, including different types of subscriber terminals (10-15) and switching modules (4-6), and where the... |
| 5067153 |
Method for transmitting subscriber data in communication systems from one secret subscriber equipment to another |
| Nov-19-1991 |
A transmission of subscriber data occurs between subscriber equipment in communication systems in order to be able to display such subscriber data on a display of subscriber equipment of a call partner.... |
| 5062136 |
Telecommunications system and method |
| Oct-29-1991 |
A teleconferencing system includes desktop computers, external cameras and eripheral apparatus to allow interconnection of two or more terminals to engage in teleconferencing via digital data networks.... |
| 5058163 |
Interface unit for transferring digital data between time-domain multiplexed communication links |
| Oct-15-1991 |
An apparatus for transferring digital data between time-domain multiplexed communication links of a telephone system which forms part of a computer network. A time-domain multiplexed communication link... |
| 5058156 |
Network interface and communication terminal |
| Oct-15-1991 |
According to the invention, for connections between terminals connected to different networks, the terminals intended for connection to the network having the higher capacity are so equipped that, alternatively... |
| 5014315 |
Digital telephone system |
| May-7-1991 |
A digital telephone system, having a through-switching module connected by its inputs/outputs to "1" subscriber concentration modules, each with group subscriber inputs/outputs connected via remote subscriber... |
| 5003593 |
Teleconferencing method for a secure key management system |
| Mar-26-1991 |
A secure teleconferencing method for a key management system is shown. This method directly establishes a secure teleconference among a number of terminals without the intervention of a certifying authority.... |
| 4972479 |
Method and apparatus for providing privacy/security in a communication system |
| Nov-20-1990 |
Apparatus and methods are disclosed for providing privacy on communications systems which include radio links, such as cellular telephone, marine radiotelephone, IMTS, and RDSS systems, in a manner which... |
| 4937862 |
Remote monitoring device |
| Jun-26-1990 |
A miniaturized DNR monitoring device is adapted to communicate over a telephone line, or otherwise, with a remote unit which may also communicate with other monitoring units. The monitoring device includes... |
| 4920567 |
Secure telephone terminal |
| Apr-24-1990 |
A secure Telephone Terminal apparatus and method is disclosed which permits clear analog or coded digital message signals to operate on a non-secure telephone network having conventional equipment. This... |
| 4920565 |
Method for connection of secure conference calls |
| Apr-24-1990 |
The present invention provides a method and apparatus of making secure conference calls in which the bridging unit does not need to know any encryption keys and can function independently of the encryption... |
| 4897875 |
Key management system for open communication environments |
| Jan-30-1990 |
A telecommunications security device for use on the communication medium includes a first and a second security unit each arranged to be inserted into for example the telephone line adjacent a user device.... |
| 4893340 |
Multijunction unit apparatus for use in a digital network |
| Jan-9-1990 |
Disclosed is an adaptive multijunction unit apparatus for multiplexing data streams between a master computer and a plurality of slave computers coupled through telephone system communication lines. The... |
| 4873721 |
Device for starting charging in a pay phone |
| Oct-10-1989 |
The present invention relates to a device for starting telephone charging in a pay phone. The starting device essentially comprises a scrambler circuit (42) which is inserted in the line (26) when the... |
| 4866771 |
Signaling system |
| Sep-12-1989 |
Periodic components of a data signal are generated from a periodic original signal in a manner to cause the periodic components to represent not only the data but also information about characteristics... |
| 4845749 |
Secure teleconferencing system |
| Jul-4-1989 |
A secure audio teleconferencing system is disclosed. The secure teleconferencing system comprises a centralized facility or bridge to which a plurality of participants is connected. The role of the bridge... |
| 4823389 |
Method and circuit apparatus for checking the authorization of access to a signal processing system |
| Apr-18-1989 |
For checking authorization of access to a signal processing system (SVS) from designated peripheral units (TE, BS) connected with the system, for the purpose of transmitting and, if the occasion arises,... |
| 4815128 |
Gateway system and method for interconnecting telephone calls with a digital voice protected radio network |
| Mar-21-1989 |
A Gateway apparatus and method is disclosed which permits secure, end-to-end communications to exchange automatically between predetermined authorized subscribers operating on a radio network and a telephone... |
| 4802220 |
Method and apparatus for multi-channel communication security |
| Jan-31-1989 |
A multi-channel communication security system where the information in an original information message is split among a number of channels in accordance with a message splitting routine such that the interception... |
| 4794644 |
Method of secured communications in a telecommunications system |
| Dec-27-1988 |
The Telecommunications system includes at least two exchanges and a plurality of user equipments. Each equipment includes a store for holding a user variable data word particular to that user. Each exchange... |
| 4763351 |
Computer security system |
| Aug-9-1988 |
A computer security system employs a first telephone line for controlling a security unit which connects a second telephone line to the computer. Each authorized user must have a user security unit generating... |
| 4531023 |
Computer security system for a time shared computer accessed over telephone lines |
| Jul-23-1985 |
A time-shared central computer can be protected from access from unauthorized users by utilizing automatic tracing equipment included within telephone switching systems, in combination with an independently... |
| 4484025 |
System for enciphering and deciphering data |
| Nov-20-1984 |
A system and method for transmitting enciphered data between first and second terminals over a data transmission channel. The system comprises a transmitter located at the first terminal, a receiver located... |
| 4449247 |
Local orderwire facility for fiber optic communication system |
| May-15-1984 |
An orderwire communication scheme for a fiber optic communication network includes terminal station equipment associated with the central offices at opposite ends of the network and signal regenerator... |
| 4398062 |
Apparatus for privacy transmission in system having bandwidth constraint |
| Aug-9-1983 |
Source intelligence within a predetermined bandwidth is normally provided to a transmission channel having a bandwidth constraint of the predetermined bandwidth. For privacy transmission, a first pulse... |
| 4232194 |
Voice encryption system |
| Nov-4-1980 |
An apparatus and method of voice encryption uses segment swapping. Features of the invention include weighting the input time-function segments by a Hamming or Hanning Window function, before converting... |
| 4228321 |
Privacy transmission system with remote key control |
| Oct-14-1980 |
In the prior art key control signals are produced at a scrambling location, used at that location for scrambling and then transmitted along with the scrambled message to the unscrambling location. In accordance... |
| 4182933 |
Secure communication system with remote key setting |
| Jan-8-1980 |
An apparatus for maintaining secure communication between subscribers. A trally located key distribution center, which includes a data processor, is utilized as a source of remotely selected working variables... |
| 4086435 |
Method of and means for scrambling and descrambling speech at audio frequencies |
| Apr-25-1978 |
Processing an input audio-frequency analog signal, for example, speech, which is to be passed through a communication channel, includes performing an n-level digitizing of the input signal, transforming... |
| 4020285 |
Voice security method and system |
| Apr-26-1977 |
The specification discloses a voice scrambler technique wherein a voice signal is split into a plurality of discrete frequency sub-bands. A random code generator generates a randomized sequence of digital... |
| 4013837 |
Voice security method and system |
| Mar-22-1977 |
The specification discloses a voice scrambler technique wherein a voice signal is split into a plurality of discrete frequency sub-bands. A random code generator generates a randomized sequence of digital... |
| 3991271 |
Voice security method and system |
| Nov-9-1976 |
The specification discloses a voice scrambler technique wherein a voice signal is split into a plurality of discrete frequency sub-bands. A random code genertor generates a randomized sequence of digital... |
