Other

Tel-e-tel, Inc.

Richard E Erett

Wayne W Chou

Joseph M Kulinets

A method of protecting computer software is provided by storing a first key in a plug-in hardware device, storing an algorithm for processing a purality of keys including the first key in software to be protected, loading the software containing the algorithm in the computer and plugging in a hardware device in a communications port of the computer. A second key, external to the software, to be protected which bears a relationship to the first key by the algorithm is loaded into the computer where processing takes place of the first and second keys in the algorithm for deriving a control key, if present, for the continued processing of the software being protected. The step of loading the second key is performed using a computer keyboard, any input/output port, a hard disk file or any other method of entry in the computer. Additional keys external to the software which bear a relationship to the first and second keys configured in the algorithm may be provided.

Method of protecting computer software from unauthorized execution using

A hardware device containing a first permanent key and a second key is plugged in a specified port of a computer to establish a communication path between the hardware device and computer. The first and second keys are presented with an access sequence from the computer in the software which is desired to be controlled generating outputs which are applied to an algorithm decoder which provides a control key which is used to protect the software from unauthorized use. The control key is the resultant of the algorithm decoder and the first and second keys. One of the keys is supplied with the hardware under the control of the developer whereas the second key may be supplied with the hardware device but is not restricted to the hardware device and may be entered through a separate port of the computer. The algorithm decoder can be included in any part of the software, the computer hardware or any combination thereof. Many combinations of the first and second keys may be designed to produce the same control key when decoded. One of the keys may be altered without regard to security, but there are certain values of the second key for each given value of the first key which will operate the software. Providing a plurality of first and matching second keys which produce the plurality of different valid control keys allows the use of additional software that works in conjunction with the original distributed software acquired at a later date without the addition of additional hardware device.

Method and apparatus for protecting multiple copies of computer software

Filter networks are incorporated within a software protection hardware device which is plugged into a communications port of a computer which device will select bits or combinations of bits emanating from the communications port resulting from commands of a controlling software in use with the computer which is desired to be protected. The filter networks select the bits of a disguised predetermined control code which when matched with a stored reference code results in an output from the filter used to activate functions within the protection device. A stream of bits including a disguised predetermined control code issuing from the computer through the security device are compared with a stored reference code in a programmable memory. When a match occurs an output emanates providing an acknowledgment code to the computer indicating that the hardware device has been plugged in and is a proper one. The stored reference code can be provided by a programmable memory using an intermediate storage register between the programmable memory and the selection network. The intermediate storage register is clocked changing the reference code in a predetermined manner. Accordingly, the reference code is changed in accordance with what is stored in the programmable memory and by the content of an intermediate register at any given time, the effect of which is to continually change the reference code by clocking the intermediate register.

Method and apparatus for protecting computer software utilizing coded

A method and apparatus are provided for protecting computer software using an active coded hardware apparatus which is adapted to be connected by an interface connector to a communications port of a computer. The computer is directed by a coded software program in which a small section of the code of the computer software interrogates the communications port periodically to determine if the active coded hardware device is present and connected. The active coded hardware device has a permanently established preset code on an active presettable counter circuit which code is transmitted when interrogated. If the active coded hardware device is present when interrogated and the correct code returned through the communications port of the computer, the program is permitted to continue insuring that the software is properly protected at all times. The active coded hardware device with its particular code and circuitry are sealed in epoxy as a deterrent against tampering. In order to violate the hardware it would be necessary to construct a duplicate of the hardware device in order to run a second copy of the software. Since the device is active containing electrical logical elements the degree in duplicating the device and its function without the benefit of circuit diagrams will be greater than the software itself. The particular hardware may be used alone or will permit daisy-chaining allowing 2, 3 or even an entire family of other elements with their own individual codes to operate simultaneously and at the same time permit computer peripherals to remain connected to the same port. A variety of time and logic elements may be added to the basic configuration in order to increase the difficulty of duplicating or violating the system.

Method and apparatus for protecting computer software utilizing an

A communication system is provided which allows closed circuit television pictures to be transmitted from conventional TV cameras to conventional monitors via an ordinary pair of wires, for example, telephone wires, lamp cord, BX cable, etc., over limited distances without measurable degradation of picture quality. A balanced system is provided with dual inputs and outputs so that the system can accommodate simultaneous transmission of audio or other data. Adapters are provided on the receiving end and on the sending end which provide conversion, impedance matching, and the frequency compensation required in order to provide uniform frequency response for the quality transmission of television as well as audio and/or other data.

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Stamford, CT, United States of America

Richard E Erett