Method for prolonging service life of power-down protection date buffer memory and smart card

Abstract

The invention relates to a method for protecting data in an order execution process and prolonging service life of a power-down protection date buffer memory and a smart card when the smart card is in the working state, the power is accidentally cut and the card is maliciously pulled out. A power-down protection sub-system in a smart card operation system comprises a random number generating module, a power-down protection control item, a power-down protection control register, a power-down protection data buffer memory block, a power-down protection data buffer memory control method and a power-down protection data recovery control method, which work cooperatively together; by randomly selecting different power-down protection data buffer memory blocks and a transferring sequence of controlled protection states, the purpose of either storing unchangeable date in a date memory in the smart card before executing the order or integrally storing all obtained new data after executing the order is realized to enable the read-write operation times of all power-down protection data blocks, a control register and a parameter register are almost equal, so as to efficiently prolonge the service life of the power-down protection date buffer memory in the smart card and enhance the fault tolerance of the power-down protection data buffer memory.

Description

technical field [0001] The invention belongs to the design field of smart cards and smart card operating systems, and in particular relates to a method for improving the service life of a power-down protection data buffer memory by performing data protection during command execution when the smart card accidentally loses power or maliciously inserts or removes the card during the working process, and smart card. Background technique [0002] A smart card is an embedded system that integrates a CPU and a control module, a security function module (including a random number generator), a memory module, a contact and / or contactless interface module, and a smart card operating system (COS). The memory system of the smart card can be divided into random access memory RAM when the CPU is working, program memory for storing COS, and EEPROM or FLASH data memory for storing user information. The capacity of each memory varies according to the type of CPU and specific applications, b...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the shortage of short service life of the existing power-failure protection data buffer memory and provide a method and smart card for improving the service life of power-failure protection data buffer memory, its (N×(256+16+2)) Section power-down data buffer storage area, the storage area is divided into N 16-byte control items, N blocks of 256-byte data buffer storage blocks and 2N-byte power-down protection block number storage control items. During power-down protection operation, randomly select one of the control items and a data buffer storage block as the power-down protection data buffer memory, and complete the data and control item buffer storage operation of power-down protection, so that each power-down protection data buffer storage block and control The number of reads and writes of items tends to be equal, thereby improving the service life of the power-down protection data buffer memory

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