With the continuous application of contactless logic encryption card, the defects of contactless logic encryption card technology are increasingly exposed, which makes it difficult to meet higher security and more complex application requirements. Especially in October 2008, there appeared a method to crack the password of mifreclassic chip (hereinafter referred to as M1 chip) on the Internet. Criminals can use this method to illegally recharge or copy various "all-in-one cards" and IC access cards using this chip at a very low economic cost, which poses a great threat to social security. Therefore, contactless CPU card smart card technology is becoming a choice for technology upgrading. Let's popularize the knowledge of IC card.

Key management system, also known as kms, is the core part of IC Engineering Security. In the whole life cycle of IC card application, how to manage the key safely?

1、 The security authentication of contactless logical encryption smart card connector is verified by Keya and keyb which are independent of each sector. The read-write security control of sector data is realized by different security combination of Keya and keyb sector control words. The personalization of non-contact logic encryption card is also very simple, mainly including the update of data and Keya, keyb sectors. All sensitive data of sim900a card holder, including Keya and keyb, are directly updated in plaintext format.

Because Keya and keyb verification mechanism can only solve the problem of card verification, smart card connector pins can not solve the problem of card terminal verification, which is what we call "fake card" problem.

The key of non-contact logic encryption smart card connector is a pre-set fixed password. No matter what method is used to calculate the key, it must be consistent with the original fixed password to read and write the protected data. So no matter it is one card one secret or unified password system, after deciphering, it can realize the decryption of contactless logic encryption IC card. Many people think that key decryption can be avoided as long as one card one secret, real-time online system or contactless logic encryption smart card connector ID is used. In fact, contactless logic encryption smart card connector ID can be used ID decryption means that the M1 card can be copied, and the IC card holder interface can avoid illegal recharge by using the on-line system, but illegal consumption can not be guaranteed, that is, illegal consumption can be carried out by copying an ID number that is the same as the M1 card ID. The current technology can be completely replicated with FPGA. According to this principle, M1 access card is not safe.