Microprocessor with coprocessing capabilities for secure transactions and quick clearing capabilities

• US 6,219,789 B1
• Filed: 09/15/1998
• Issued: 04/17/2001
• Est. Priority Date: 07/20/1995
• Status: Expired due to Term

• Current Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Original Assignee: Dallas Semiconductor Corporation (Analog Devices, Inc.)
• Inventors: Grider, Stephen N., Bartling, James E., Little, Wendell, Curiger, Andreas, Harrington, Bradley M., Bunsey, David A., Liu, Shyun
• Primary Examiner(s): LE, DIEU MINH T
• Application Number:
  US09/153,475
• Time in Patent Office: 945 Days
• Field of Search: 713/200, 713/201, 714/5, 714/29, 714/42, 714/54
• US Class Current: 726/34
• CPC Class Codes: G06F 11/1004 to protect a block of data words, e.g. CRC or checksum G06F11/1076 takes precedence; security arrangements for protecting computers or computer systems against unauthorized activity G06F21/00
• CPC Class Codes: G06F 21/602 Providing cryptographic facilities or services
• CPC Class Codes: G06F 21/72 in cryptographic circuits
• CPC Class Codes: G06F 21/73 by creating or determining hardware identification, e.g. serial numbers
• CPC Class Codes: G06F 21/81 by operating on the power supply, e.g. enabling or disabling power-on, sleep or resume operations
• CPC Class Codes: G06F 21/86 Secure or tamper-resistant housings
• CPC Class Codes: G06F 21/87 by means of encapsulation, e.g. for integrated circuits
• CPC Class Codes: G06F 2211/007 Encryption, En-/decode, En-/decipher, En-/decypher, Scramble, (De-)compress
• CPC Class Codes: G06F 2221/2143 Clearing memory, e.g. to prevent the data from being stolen
• CPC Class Codes: G06F 2221/2153 Using hardware token as a secondary aspect
• CPC Class Codes: G06F 7/588 Random number generators, i.e. based on natural stochastic processes
• CPC Class Codes: G06F 9/30134 Register stacks; shift registers
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06Q 20/40975 using encryption therefor
• CPC Class Codes: G07F 7/082 Features insuring the integrity of the data on or in the card
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• CPC Class Codes: G11C 5/06 Arrangements for interconnecting storage elements electrically, e.g. by wiring
• CPC Class Codes: G11C 5/143 Detection of memory cassette insertion or removal; Continuity checks of supply or ground lines; Detection of supply variations, interruptions or levels G11C5/148 takes precedence; Switching between alternative supplies G11C5/141 takes precedence
• CPC Class Codes: G11C 7/24 Memory cell safety or protection circuits, e.g. arrangements for preventing inadvertent reading or writing; Status cells; Test cells
• CPC Class Codes: G11C 8/20 Address safety or protection circuits, i.e. arrangements for preventing unauthorized or accidental access
• CPC Class Codes: H01L 2224/16225 : the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 23/57 : Protection from inspection, reverse engineering or tampering
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H04L 25/026 : Arrangements for coupling transmitters, receivers or transceivers to transmission lines; Line drivers duplexing arrangements H04L5/14
• CPC Class Codes: Y10S 257/922 : with means to prevent inspection of or tampering with an integrated circuit, e.g. "smart card", anti-tamper

Abstract

An electronic module having at least a microprocessor and co-processor on a single integrated circuit. The electronic module can be contained in a small housing. The electronic module provides secure bidirectional data communication via a data bus. The electronic module may include an integrated circuit comprising a microprocessor, and a co-processor adapted to handle 1,024-bit modulo mathematics primarily aimed at RSA calculations. The electronic module is preferably contained in a small token sized metallic container and will preferably communicate via a single wire data bus which uses a one-wire protocol.

Claims

1. An integrated electronic circuit providing microprocessor and co-processor capabilities, said electronic circuit comprising:

an interface for bidirectionally interfacing said integrated electronic circuit to another device;

a UART circuit connected to said interface;

a microprocessor core connected to said UART circuit

a RAM memory coupled to said microprocessor core and

a clearing circuit to clear at least a portion of the contents of said RAM memory upon the detection of tamper related event.

2. The integrated electronic circuit of claim 1, further comprising a read only memory (ROM) that is programmed via a custom mask provided in the manufacturing process, said ROM being connected to said microprocessor core.

3. The integrated electronic circuit of claim 1, further comprising a coprocessor, connected to said microprocessor core, for computing encryption related mathematics.

4. The integrated electronic circuit of claim 1, further comprising a random number generator and a coprocessor circuit connected to said microprocessor core, said combination of at least said random number generator and said coprocessor circuit being for generating encryption key pairs.

5. The integrated electronic circuit of claim 1, further comprising a random access memory circuit, and

an alarm circuit for determining whether said integrated electronic circuit is being tampered with and for erasing the contents said random access memory when said integrated electronic circuit is being tampered with.

6. The integrated electronic circuit of claim 1, further comprising a random access memory circuit connected to said microprocessor core, and

an alarm circuit for resetting said integrated electronic circuit if an alarm condition occurs.

7. The integrated electronic circuit of claim 1, further comprising a random access memory circuit (RAM), connected to said microprocessor core.

8. The integrated electronic circuit of claim 7, wherein said RAM is SRAM.

9. The integrated electronic circuit of claim 1, wherein said interface is a single wire bus interface.

10. The integrated electronic circuit of claim 1, wherein said UART is a one wire UART.