Countermeasure method and device for protecting against a fault injection attack by detection of a well voltage crossing a threshold

• US 8,564,364 B2
• Filed: 03/24/2011
• Issued: 10/22/2013
• Est. Priority Date: 03/24/2010
• Status: Expired due to Fees

• Current Assignee: Stmicroelectronics Rousset SAS (STMicroelectronics NV)
• Original Assignee: Stmicroelectronics Rousset SAS (STMicroelectronics NV)
• Inventors: Marinet, Fabrice, Lisart, Mathieu
• Primary Examiner(s): Donovan, Lincoln
• Assistant Examiner(s): ENGLUND, TERRY LEE
• Application Number:
  US13/071,325
• Publication Number:
  US 20110234307A1
• Time in Patent Office: 943 Days
• Field of Search: None
• US Class Current: 327/565
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 21/72 in cryptographic circuits
• CPC Class Codes: G06K 19/07309 Means for preventing undesired reading or writing from or onto record carriers
• CPC Class Codes: H01L 21/76224 using trench refilling with dielectric materials trench filling with polycristalline silicon H01L21/763; together with vertical isolation, e.g. trench refilling in a SOI substrate H01L21/76264
• 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
• CPC Class Codes: H03K 19/003 Modifications for increasing the reliability for protection
• CPC Class Codes: H03K 3/84 Generating pulses having a predetermined statistical distribution of a parameter, e.g. random pulse generators
• CPC Class Codes: H04L 2209/12 Details relating to cryptographic hardware or logic circuitry
• CPC Class Codes: H04L 9/004 for fault attacks
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A method for detecting an attack in an electronic microcircuit comprises: forming the microcircuit in a substrate, forming in the substrate a first well electrically isolated from the substrate, by a second well and an embedded well, forming in the first and second wells a data processing circuit comprising a ground terminal formed in the first well and a power supply terminal formed in the second well, and activating a detection signal when a voltage at the ground or power supply terminal of the data processing circuit crosses a threshold voltage.

Claims

1. A method, comprising:

detecting that a voltage of at least one of a first local ground terminal and a first power supply terminal crosses a first threshold voltage, the first local ground and first power supply terminals being part of a first data processing circuit of a microcircuit in a substrate, the microcircuit including first and second wells and a first embedded region formed in the substrate, the first well being electrically isolated from a main portion of the substrate by the second well and the first embedded region;

the first local ground terminal being formed in the first well and the first power supply terminal being formed in the second well;

activating a first detection signal in response to detecting the voltage at the at least one of the first local ground and first power supply terminals of the first data processing circuit crossing the first threshold voltage; and

supplying a bias voltage to the first local ground terminal of the first data processing circuit through a resistor or a bias circuit coupling the first local ground terminal of the first data processing circuit to a ground of the substrate.

2. A method according to claim 1, wherein the activating includes activating the first detection signal in response to the voltage, being a voltage between the first local ground terminal and the ground of the substrate, crossing the first threshold voltage.

3. A method according to claim 1, wherein the activating includes activating the first detection signal in response to the voltage, being a voltage between the first power supply terminal and a ground of the substrate, going below the first threshold voltage.

4. A method according to claim 1, further comprising:

producing a regulated supply voltage by regulating a supply voltage received at a supply terminal of the microcircuit;

supplying the regulated supply voltage to the first power supply terminal, wherein;

the bias voltage is greater than a voltage received at the ground of the substrate;

the detecting includes detecting that a first voltage difference, between the first local ground terminal and the ground of the substrate, crosses the first threshold voltage, or detecting that a second voltage difference, between the first power supply terminal and the regulated supply voltage, crosses the first threshold voltage; and

the activating includes activating the first detection signal in response to detecting the first voltage difference or the second voltage difference crossing the first threshold voltage.

5. A method comprising:

detecting that a voltage of at least one of a first local ground terminal and a first power supply terminal crosses a first threshold voltage, the first local ground and first power supply terminals being part of a first data processing circuit of a microcircuit in a substrate, the microcircuit including first and second wells and a first embedded region formed in the substrate, the first well being electrically isolated from a main portion of the substrate by the second well and the first embedded region;

the first local ground terminal being formed in the first well and the first power supply terminal being formed in the second well;

activating a first detection signal in response to detecting the voltage at the at least one of the first local ground and first power supply terminals of the first data processing circuit crossing the first threshold voltage; and

adjusting the first threshold voltage to a value higher than a variation range of a local ground voltage at the first local ground terminal of the first data processing circuit in a normal operation, taking into account a ground bias voltage in relation to the ground of the substrate.

6. A method according to claim 5, wherein the activating includes activating the first detection signal in response to a voltage between the first local ground terminal and the ground of the substrate crossing the first threshold voltage.

7. A method, comprising:

detecting that a voltage of at least one of a first local ground terminal and a first power supply terminal crosses a first threshold voltage, the first local ground and first power supply terminals being part of a first data processing circuit of a microcircuit in a substrate, the microcircuit including first and second wells and a first embedded region formed in the substrate, the first well being electrically isolated from a main portion of the substrate by the second well and the first embedded region;

the first local ground terminal being formed in the first well and the first power supply terminal being formed in the second well;

activating a first detection signal in response to detecting the voltage at the at least one of the first local ground and first power supply terminals of the first data processing circuit crossing the first threshold voltage; and

adjusting the first threshold voltage to a value lower than a variation range of the voltage at the first power supply terminal of the first data processing circuit in a normal operation.

8. A method according to claim 7, wherein the activating includes activating the first detection signal in response to the voltage, being a voltage between the first power supply terminal and a ground of the substrate, going below the first threshold voltage.

9. A method

detecting that a voltage of at least one of a first local ground terminal and a first power supply terminal crosses a first threshold voltage, the first local ground and first power supply terminals being part of a first data processing circuit of a microcircuit in a substrate, the microcircuit including first and second wells and a first embedded region formed in the substrate, the first well being electrically isolated from a main portion of the substrate by the second well and the first embedded region;

the first local ground terminal being formed in the first well and the first power supply terminal being formed in the second well;

activating a first detection signal in response to detecting the voltage at the at least one of the first local ground and first power supply terminals of the first data processing circuit crossing the first threshold voltage, wherein the detecting and activating are performed using a first detection circuit;

detecting, using a second detection circuit, that a voltage of at least one of a second local ground terminal and a second power supply terminal of a second data processing circuit crosses a second threshold voltage, the second data processing circuit being part of the microcircuit, the microcircuit including third and fourth wells and a second embedded region formed in the substrate, the third well being electrically isolated from the main part of the substrate by the fourth well and the second embedded region, the second local ground terminal being formed in the third well and the second power supply terminal being formed in the fourth well; and

activating, using the second detection circuit, a second detection signal in response to detecting that the voltage of the at least one of the second local ground terminal and the second power supply terminal crosses the second threshold voltage.

10. A method according to claim 9, comprising supplying first and second bias voltages to the first and second local ground terminals, respectively, the supplying including supplying the first bias voltage using a first bias circuit and supplying the second bias voltage using a second bias circuit.

11. A method according to claim 9, comprising supplying a consolidated active detection signal if at least one of the first and second detection signals is active.

12. A microcircuit comprising:

a first data processing circuit that includes a first power supply terminal and a first local ground terminal, the first local ground terminal being positioned in a first well of a substrate, the first well being electrically isolated from a main part of the substrate by a second well of the substrate and a first embedded region of the substrate; and

a first detection circuit formed in the substrate, the first detection circuit being configured to activate a detection signal in response to detecting that a voltage of at least one of the first local ground terminal and the first power supply terminal of the first data processing circuit crosses a first threshold voltage;

a ground terminal of the substrate coupled to the first local ground terminal of the first data processing circuit; and

a bias circuit coupled between the first local ground terminal and the ground terminal of the substrate, the bias circuit being configured to supply a bias voltage to the first local ground terminal.

13. A microcircuit according to claim 12, wherein the bias circuit includes:

a resistor coupled between the first local ground terminal and the ground terminal of the substrate, the resistor being configured to supply the bias voltage to the first local ground terminal.

14. A microcircuit according to claim 12, wherein the bias circuit includes:

a comparator having first and second inputs and an output, the output being coupled to the first local ground terminal and to the second input;

a resistor coupled between the first input of the comparator and the ground terminal of the substrate; and

a current generator coupled between the first power supply terminal and the first input of the comparator.

15. A microcircuit, comprising:

a first data processing circuit that includes a first power supply terminal and a first local ground terminal, the first local ground terminal being positioned in a first well of a substrate, the first well being electrically isolated from a main part of the substrate by a second well of the substrate and a first embedded region of the substrate;

a first detection circuit formed in the substrate, the first detection circuit being configured to activate a first detection signal in response to detecting that a voltage of at least one of the first local ground terminal and the first power supply terminal of the first data processing circuit crosses a first threshold voltage;

a second data processing circuit that includes a second power supply terminal and a second local ground terminal, the second local ground terminal being formed in a third well of the substrate, the third well being electrically isolated from the main part of the substrate by a fourth well of the substrate and a second embedded region of the substrate; and

a second detection circuit formed in the substrate, the second detection circuit being configured to activate a second detection signal in response to a voltage of at least one of the second local ground terminal and the second power supply terminal crosses a second threshold voltage.

16. A microcircuit according to claim 15, further comprising a logic circuit configured to receive the first and second detection signals and supply an active consolidated detection signal if at least one of the first and second detection signals is active.

17. A microcircuit according to claim 15, further comprising:

a first bias circuit configured to supply a first bias voltage to the first local ground terminal; and

a second bias circuit configured to supply a second bias voltage to the second local ground terminal.

18. A microcircuit portable device, comprising:

a support; and

a microcircuit carried by the support and including;

a first data processing circuit that includes a first power supply terminal and a first local ground terminal, the first local ground terminal being positioned in a first well of a substrate, the first well being electrically isolated from a main part of the substrate by a second well of the substrate and a first embedded region of the substrate;

a first detection circuit formed in the substrate, the first detection circuit being configured to activate a detection signal in response to detecting that a voltage of at least one of the first local ground terminal and the first power supply terminal of the first data processing circuit crosses a first threshold voltage;

a ground terminal of the substrate coupled to the first local ground terminal of the first data processing circuit; and

a bias circuit coupled between the first local ground terminal and the ground terminal of the substrate, the bias circuit being configured to supply a bias voltage to the first local ground terminal.

19. A microcircuit portable device according to claim 18, wherein the bias circuit includes:

a resistor coupled between the first local ground terminal and the ground terminal of the substrate, the resistor being configured to supply the bias voltage to the first local ground terminal.

20. A microcircuit portable device according to claim 18, wherein the bias circuit includes:

a comparator having first and second inputs and an output, the output being coupled to the first local ground terminal and to the second input;

a resistor coupled between the first input of the comparator and the ground terminal of the substrate; and

a current generator coupled between the first power supply terminal and the first input of the comparator.

21. A microcircuit portable device, comprising:

a support; and

a microcircuit carried by the support and including;

a first data processing circuit that includes a first power supply terminal and a first local ground terminal, the first local ground terminal being positioned in a first well of a substrate, the first well being electrically isolated from a main part of the substrate by a second well of the substrate and a first embedded region of the substrate;

a first detection circuit formed in the substrate, the first detection circuit being configured to activate a first detection signal in response to detecting that a voltage of at least one of the first local ground terminal and the first power supply terminal of the first data processing circuit crosses a first threshold voltage;

a second data processing circuit that includes a second power supply terminal and a second local ground terminal, the second local ground terminal being formed in a third well of the substrate, the third well being electrically isolated from the main part of the substrate by a fourth well of the substrate and a second embedded region of the substrate; and

a second detection circuit formed in the substrate, the second detection circuit being configured to activate a second detection signal in response to a voltage of at least one of the second local ground terminal and the second power supply terminal crosses a second threshold voltage.

22. A microcircuit portable device according to claim 21, wherein the microcircuit further includes a logic circuit configured to receive the first and second detection signals and supply an active consolidated detection signal if at least one of the first and second detection signals is active.

23. A microcircuit portable device according to claim 21, wherein the microcircuit further includes:

a first bias circuit configured to supply a first bias voltage to the first local ground terminal; and

a second bias circuit configured to supply a second bias voltage to the second local ground terminal.