Intelligent security device

• US 5,343,524 A
• Filed: 06/21/1991
• Issued: 08/30/1994
• Est. Priority Date: 06/21/1991
• Status: Expired due to Fees

• Current Assignee: Feiying Chen, Kai J. Chin, Xiao-Chun Mu
• Original Assignee: Feiying Chen, Kai J. Chin, Xiao-Chun Mu
• Inventors: Mu, Xiao-Chun, Chin, Kai J., Chen, Feiying
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US07/718,603
• Time in Patent Office: 1,166 Days
• Field of Search: 380/4, 380/25
• US Class Current: 705/55
• CPC Class Codes: G06F 21/123 by using dedicated hardware, e.g. dongles, smart cards, cryptographic processors, global positioning systems [GPS] devices
• CPC Class Codes: G06F 2221/2137 Time limited access, e.g. to a computer or data

Abstract

An intelligent security device (10) is disclosed for protecting computer software from unauthorized use. The security device (10) is a hardware device having within a microprocessor (36) for interacting with a host computer (32) such that protected software may not be operated unless the security device (10) is in place. Physical duplication of the security device (10) will not result in a workable copy, due to the nature of the microprocessor (36), which is such that information is encoded therein and further such that encryption codes are also stored therein and cannot be discovered after the microprocessor (36) is locked by any known means. A system clock (21) within the microprocessor (36) is adaptable to the purpose of permitting use of the protected software only within limited time parameters.

Claims

1. A software protection device for connection to a communications port of a host computer, comprising:

a memory for storing data therein in an encoded form;

processing means for encoding data to be stored in said memory, and further for decoding data to be retrieved from said memory, and further for performing calculations on the data;

data level conversion means for connecting said processing means to the host computer such that data output from the host computer is converted into a form usable by said processing means, and further such that data output from said processing means is converted into a form usable by said host computer; and

power isolation means for interconnecting the software protection device to the host computer such that the software protection device draws operating power from the host computer, wherein;

said processing means uses a data encryption scheme stored in said memory to encode and to decode the data;

a code is required to access said data encryption scheme

said memory and said processing means being components of the software protection device provided for supplementing the computer which are housed together in a unitary integrated circuit device package such that data contained within said memory can only be retrieved in usable form by the operation of decoding the data through said processing means.

2. The software protection device of claim 1, and further including:

data line interrupt means for selectively temporarily interrupting a plurality of computer serial interface data lines, such that the flow of data through the communications portion of the host computer can be temporarily interrupted to enable communications between said processing means and the host computer, and further for selectively temporarily reinstating the plurality of computer serial interface data lines such that the host computer can send and receive data through the communications port.

3. The software protection device of claim 1, wherein:

said memory includes instructions for causing said processing means to provide a protection device identifying code to the host computer.

4. The software protection device of claim 1, wherein said memory includes instructions for:

causing said processing means to read a software identifying code from the host computer;

compare, within said processing means, the software identifying code to an expected software code residing within the microprocessor; and

permit the host computer to proceed in operation when the software identifying code matches the expected software code.

5. The software protection device of claim 1, wherein said memory includes instructions for:

reading from a clock with said processing means a current time;

comparing the current time to a time parameter limitation residing within said processing means; and

permitting the host computer to proceed in operation when the current time is within the time parameter limitation.

6. The software protection device of claim 1, wherein said memory includes instructions for:

causing said processing means to perform a calculation;

returning a calculated result of the calculation to the host computer;

comparing, within the host computer, the calculated result to an expected result residing with the host computer; and

permitting the host computer to proceed in operation when the calculated result matches the expected result.

7. The software protection device of claim 1, wherein said memory includes instructions for:

causing said processing means to act as a coprocessor in that the host computer can assign calculations to said processing means, the results of which are returned to the host computer.