Method and circuit for realizing mcu security

A security and circuit technology, applied in the field of high-security MCU, can solve the problems of high cost and increase intruder's cracking cost, and achieve the effect of enhancing security, increasing cracking cost, and improving market competitiveness

Active Publication Date: 2018-04-27
SHANGHAI HUAHONG INTEGRATED CIRCUIT
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Now more and more popular MCUs use the fuse bit with the same wiring layout as the storage array, and even make the fuse bit inside the storage device. This safe fuse bit is difficult to be cracked by intruders, but it takes more time for intruders The cost can still be resolved
For example, the MCUs of TI and Renesas now use security keys for protection, which greatly increases the cost of cracking for intruders.

Method used

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  • Method and circuit for realizing mcu security
  • Method and circuit for realizing mcu security
  • Method and circuit for realizing mcu security

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Embodiment Construction

[0029] see image 3 As shown, the method for realizing the high security of the MCU equates the security key into a fuse circuit, and stores the security key in the internal location of the Flash memory, and adopts this method to protect the security of sensitive information. And the wiring of the logic circuit of the password protection circuit uses the MCU chip instead of the bottom two metal layers of the circuit board for winding, which strengthens the password protection of the circuit. image 3 The dots in the box indicate the area where the security key is stored. The power-on reset adaptive circuit is used to read different addresses, and the security key is combined with the main program, so that intruders cannot find the location of the security key at all. In this way, intruders cannot use the intrusive FIB method to crack the fuse circuit at all. If ultraviolet light is used, the overall information will be destroyed and the meaning of cracking will be lost.

[00...

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Abstract

The invention discloses a method for realizing the safety of an MCU (micro controller unit). After the MCU is power-on, a main reset signal in an MCU chip is set to '1' by utilizing a power supply monitoring circuit, then an RC oscillation circuit in the MCU chip is started, and a power-on reset adaptive circuit is started at the same time; the power-on reset adaptive circuit immediately reads a 128-bit security key stored in a safety position of an Flash; the security key is stored in a password matching circuit and then the main reset signal is released; a JTAG (joint test action group) debugging interface is in an off state by default; after the MCU chip works, the password matching circuit starts working; when a password is externally input, the password matching circuit is used for performing matching confirmation on the password and the security key, and after matching is confirmed to be correct, the JTAG debugging interface is on, or otherwise, erasing the whole MCU chip. The invention further discloses a circuit for realizing the safety of the MCU. The method and the circuit can improve the safety of the ultra-low-power MCU and greatly increase the cracking cost of an invader.

Description

technical field [0001] The invention relates to the technical field of high security MCU (microcontroller), in particular to a method for realizing MCU security. The invention also relates to a circuit for realizing MCU safety. Background technique [0002] Generally MCU is without any special hardware security protection. They are protected based on the design of non-public algorithms, but this can be cracked by analyzing the data characteristics on the burner port and using an oscilloscope for protocol analysis (see figure 1 shown). Later, the MCU relied on Fuse (fuse) technology to ensure the safety of the MCU, but this fuse circuit is different from the normal memory, and it is easy to be located under a microscope and cracked by an intrusive FIB (Focused Ion Beam). MCU data security. The cracking method is to track the high-voltage pins through a microscope, so as to track the fuse circuit, ground the output of the fuse circuit or connect it to the power supply, and...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G05B19/04
CPCG05B19/042G05B2219/25257
Inventor 刘慧牟晨杰王永流
Owner SHANGHAI HUAHONG INTEGRATED CIRCUIT
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