Java code patching method of Java card

Abstract

The invention discloses a Java code patching method of a Java card. Two different processing methods are provided for Java codes stored in an ROM (Read Only Memory) region of the Java card and Java codes stored in an EEPROM (Electrically Erasable Programmable Read-Only Memory) region of the Java card; as for the Java codes in the ROM region, only a patch management table is allocated in advance, a multilevel patch information table method is adopted, space is not needed to be allocated to the patch information table in advance, and the patch information table is dynamically allocated during patching, so that the pre-allocated space can be greatly reduced; as for the Java codes in the EEPROM region, extra space is not needed for management, modification is performed on the address of an original method, and the operation of looking up the table is reduced, so that the implementation speed of the method is further improved. According to the Java code patching method, a user can patch the Java codes in the Java card without replacing the Java card, and the purpose of upgrading functions or repairing defects is achieved; after patching is performed, the operating efficiency of the Java card can be ensured, the demands of clients for time-sensitive application are met, client data losses caused by application program updating can be avoided, and the method has the advantage of short time required for repairing.

Description

technical field [0001] The invention relates to the field of Java smart cards, in particular to a Java code patch method for a Java card. Background technique [0002] With the overall development of financial electronics, in order to meet the needs of users for one card with multiple functions, Java cards supporting multiple applications have been more and more widely used. As a smart card, the Java card's storage system is mainly composed of read-write memory (RAM), read-only memory (ROM) and erasable programming memory (EEPROM), among which RAM is used to store intermediate data and result data in the operation process , ROM is used to store the operating system of the smart card, and EEPROM is the main memory of the smart card, which is used to store the personal information of the cardholder and the information and application data of the issuing unit. [0003] However, with changes in user needs and diversification of services, after the Java Card product is put into...

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Problems solved by technology

[0003] However, with changes in user needs and diversification of services, after the Java Card product is put into use, it is likely to have defects or require an upgrade of the function. If the Java code solidified in the Java Card ROM or EEPROM cannot be upgraded and maintained , the user needs to replace the Java card, which affects the life of the user. If the Java card used for patching and upgrading has a large space, the Java card cannot be guaranteed when processing some time-sensitive applications (such as fast payment). operation efficiency

[0004] In the existing Java card patch method, if the original program is found to have defects, generally by deleting the original program, downloading and installing a new application program, this method will cause the loss of customer data, and due to the large memory of the application program itself , requires less modification, and takes longer if the entire application is re-downloaded

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