Protection method for PCB safety circuit

Abstract

The invention discloses a protection method for a PCB safety circuit. The PCB has more than two layers and carries an onboard circuit. The onboard circuit includes the safety circuit to be protected. A safety circuit wire arrangement area of the onboard circuit is pre-arranged in the board. The safety circuit is arranged in the wire arrangement area and wires are arranged on the inner layers of the PCB. A shielding area is arranged on the surface of the PCB corresponding to the safety circuit wire arrangement area in the PCB. The shielding area is inside provided with an integrated circuit composed of integrated circuit modules having a built-in self-check function or equipped with electronic marks. The integrated circuit performs shielding protection on the safety circuit in the PCB. The integrated circuit modules in the shielding area are used for circuit self-check or circuit function guidance for the onboard circuit of the PCB board. According to the invention, protection of the PCB safety circuit can be achieved at a comparatively low cost.

Description

technical field [0001] The invention relates to the field of protection of electronic circuits, in particular to a method for protecting safety circuits of PCB boards. Background technique [0002] At present, electronic products are widely used in financial transactions, and there are more and more devices involving human-computer interaction in transactions. For example, the circuit on the PCB board of the device that involves information security is implanted by malicious attackers into eavesdropping devices, or implanted with tampering circuits. Then when the customer enters the password on the human-computer interaction device, the password will be stolen by the attacker. Therefore, how to protect the circuit security of the PCB board and prevent it from being maliciously implanted with external circuits is a research on the manufacturing process of the PCB board. direction. [0003] An existing safety line protection method is as attached figure 1 As shown, usually a...

AI Technical Summary

Problems solved by technology

[0003] An existing safety line protection method is as attached figure 1 As shown, usually a multi-layer PCB board is used, and metal meshes (12) are arranged in the PCB layers on both sides of the layer where the safe circuit wiring area (13) needs to be protected, so that it is difficult for the attacker to touch the specific circuit, but this method Among them, the area where the metal mesh is located cannot be used for wiring, which increases the number of layers of the PCB board and increases the manufacturing cost, and if the design of the metal mesh is not good, when the PCB board circuit works at high frequency or very high frequency It is easy to affect the circuit work of the PCB board due to interference signals generated by electromagnetic induction. In addition, when using this method, it cannot prevent the attacker from polishing the PCB board to remove the metal mesh to achieve the purpose of attack.

[0004] There is still a safe line protection method is to set up a self-destruct attack protection circuit on the PCB board, and self-destruct the data in the circuit chip when an attack behavior is found, but this also has the problem of increasing costs.

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