Apparatus for protecting an integrated circuit formed in a substrate and method for protecting the circuit against reverse engineering

• US 6,798,234 B2
• Filed: 02/19/2003
• Issued: 09/28/2004
• Est. Priority Date: 08/21/2000
• Status: Expired due to Term

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Laackmann, Peter, Taddiken, Hans
• Primary Examiner(s): LE, DON P
• Application Number:
  US10/368,787
• Publication Number:
  US 20030132777A1
• Time in Patent Office: 587 Days
• Field of Search: 326/14, 326/16, 326/21, 326/82, 326/83
• US Class Current: 326/21
• CPC Class Codes: G06K 19/07372 by detecting tampering with the circuit
• CPC Class Codes: H01L 23/576 using active circuits
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

An apparatus for protecting an integrated circuit formed in a substrate and a method for protecting the integrated circuit against reverse engineering includes an active shield having a signal transmitter, a signal receiver, at least two conductor tracks running between the signal transmitter and the signal receiver, and a drive and evaluation device connected to the signal transmitter and to the signal receiver. The shield at least partially covers the integrated circuit. A covering composition applied on the substrate forms a mechanical protection of the integrated circuit. The shield has a switching apparatus. As a result, a capacitive measurement method can be carried out in a first switching state and damage to the shield can be detected in a second switching state.

Claims

1. An apparatus for protecting an integrated circuit formed in a substrate, comprising:

a shield at least partially covering the integrated circuit, said shield having;

a signal transmitter;

a signal receiver;

at least two conductor tracks running between said signal transmitter and said signal receiver;

a drive and evaluation device connected to said signal transmitter and to said signal receiver;

a covering applied on the substrate; and

a switching apparatus having;

a first switching state enabling a capacitive measurement; and

a second switching state enabling detection of damage to said shield.

2. The apparatus according to claim 1, wherein:

said at least two conductor tracks have a portion; and

said switching apparatus is disposed in said portion of said at least two conductor tracks.

3. The apparatus according to claim 1, wherein said switching apparatus has a plurality of switches disposed in at least one of said at least two conductor tracks.

4. The apparatus according to claim 1, wherein said switching apparatus has a plurality of switches each respectively disposed in one of said at least two conductor tracks.

5. The apparatus according to claim 1, wherein two of said at least two conductor tracks are adjacent one another with a capacitive coupling.

6. The apparatus according to claim 1, wherein two of said at least two conductor tracks are disposed with respect to one another to form a capacitive coupling therebetween.

7. The apparatus according to claim 5, wherein:

a first of said two conductor tracks has a switch;

a second of said two conductor tracks does not have a switch; and

said first conductor track and said second conductor track are adjacent one another with a capacitive coupling.

8. The apparatus according to claim 6, wherein:

a first of said two conductor tracks has a switch;

a second of said two conductor tracks does not have a switch; and

said first conductor track and said second conductor track are disposed with respect to one another to form a capacitive coupling therebetween.

9. The apparatus according to claim 7, wherein said first and second conductor tracks are directly adjacent to one another.

10. The apparatus according to claim 8, wherein said first and second conductor tracks are directly adjacent to one another.

11. The apparatus according to claim 7, including at least one further conductor track disposed between said first and second conductor tracks.

12. The apparatus according to claim 8, including at least one further conductor track disposed between said first and second conductor tracks.

13. The apparatus according to claim 11, wherein said at least one further conductor track is a floating conductor track.

14. The apparatus according to claim 12, wherein said at least one further conductor track is a floating conductor track.

15. The apparatus according to claim 1, wherein:

said switching apparatus has a plurality of switches connected to said drive and evaluation device; and

said drive and evaluation device controls said switches.

16. The apparatus according to claim 3, wherein:

said switches are connected to said drive and evaluation device; and

said drive and evaluation device controls said switches.

17. The apparatus according to claim 4, wherein:

said switches are connected to said drive and evaluation device; and

said drive and evaluation device controls said switches.

18. The apparatus according to claim 1, wherein said signal receiver is connected to said drive and evaluation device.

19. The apparatus according to claim 1, wherein said switching apparatus is part of said signal transmitter.

23. A method for protecting an integrated circuit formed in a substrate against reverse engineering, which comprises:

providing an apparatus according to claim 1;

selecting one of the first and second switching states of the switching apparatus with the drive and evaluation device;

applying a respective signal to the at least two conductor tracks with the transmitting device;

evaluating a signal received by the signal receiver with the drive and evaluation device; and

if the evaluation of the signal by the drive and evaluation device produces an unexpected result, then initiating a function change of the integrated circuit, and if the evaluation of the signal by the drive and evaluation device produces an expected result, repeating the selecting, applying and evaluating steps.

24. The method according to claim 23, which further comprises selecting the one switching state one of optionally and alternately with the drive and evaluation apparatus.

25. The method according to claim 23, which further comprises optionally selecting the one switching state with the drive and evaluation apparatus.

26. The method according to claim 23, which further comprises alternately selecting the one switching state with the drive and evaluation apparatus.

27. The apparatus according to claim 23, which further comprises changing the one switching state one of periodically and at random time intervals.

28. The apparatus according to claim 23, which further comprises periodically changing the one switching state.

29. The apparatus according to claim 23, which further comprises changing the one switching state at random time intervals.

30. The method according to claim 23, which further comprises at least signals present on one of the at least two conductor tracks with a switch and an adjacent other one of the at least two conductor tracks without a switch being different if the switching apparatus is in the second switching state.

31. The method according to claim 23, which further comprises

placing a switch on a first of the at least two conductor tracks, the one conductor track being adjacent to a second of the at least two conductor tracks without a switch;

applying a first signal to the first conductor track with the transmitting device; and

applying a second signal to the second conductor track with the transmitting device, the first and second signal being different when the switching apparatus is in the second switching state.

20. An apparatus for protecting an integrated circuit formed in a substrate, comprising:

a shield adapted to at least partially cover the integrated circuit, said shield having;

a signal transmitter;

a signal receiver;

at least two conductor tracks running between said signal transmitter and said signal receiver;

a drive and evaluation device connected to said signal transmitter and to said signal receiver;

a covering adapted to be applied on the substrate; and

a switching apparatus having;

a first switching state enabling capacitive coupling between said at least two conductor tracks; and

a second switching state disabling capacitive coupling between said at least two conductor tracks and, thereby, enabling detection of damage to said shield.

21. An integrated circuit protecting apparatus for protecting an integrated circuit formed in a substrate, comprising:

a shield adapted to at least partially cover the integrated circuit, said shield having;

a signal transmitter;

a signal receiver;

at least two conductor tracks connecting said signal transmitter and said signal receiver;

a drive and evaluation device connected to said signal transmitter and to said signal receiver;

a covering adapted to be applied on the substrate; and

a switching apparatus programmed to perform a capacitive measurement method in a first switching state and programmed to detect damage to said shield in a second switching state.

22. In an integrated circuit formed in a substrate, an apparatus for protecting the integrated circuit comprising:

a shield at least partially covering the integrated circuit, said shield having;

a signal transmitter;

a signal receiver;

at least two conductor tracks running between said signal transmitter and said signal receiver and connecting said signal transmitter to said signal receiver;

a drive and evaluation device connected to said signal transmitter and to said signal receiver;

a covering applied on the substrate; and

a switching apparatus having;

a first switching state enabling capacitive coupling between said at least two conductor tracks; and

a second switching state disabling capacitive coupling between said at least two conductor tracks and, thereby, enabling detection of damage to said shield.

32. A method for protecting an integrated circuit formed in a substrate against reverse engineering, which comprises:

at least partially covering the integrated circuit with a shield having;

a signal transmitter;

a signal receiver;

at least two conductor tracks running between the signal transmitter and the signal receiver;

a drive and evaluation device connected to the signal transmitter and to the signal receiver;

a covering applied on the substrate; and

a switching apparatus having;

a first switching state enabling a capacitive measurement; and

a second switching state enabling detection of damage to the shield;

selecting one of the first and second switching states with the drive and evaluation device;

applying a respective signal to the at least two conductor tracks with the transmitting device;

evaluating a signal received by the signal receiver with the drive and evaluation device; and

if the evaluation of the signal by the drive and evaluation device produces an unexpected result, then initiating a function change of the integrated circuit, and if the evaluation of the signal by the drive and evaluation device produces an expected result, repeating the selecting, applying and evaluating steps.