Analysis:
1. When the administrator stores the amount data in the card, there are generally two ways: a. Open the programmer mode with the administrator card, enter the management password, then insert the customer card into the card reader and write instructions to change the original data on the customer card, that is, increase the amount; B, directly insert the user's card into the card reader, enter the password of the writing instruction, and change the amount.
Personally, I want to change the data stream on the card-"borrow it from the card reader or management card by improper means"-"Please use the high-magnification digital zoom tool to record the password (it is recommended to use the optical zoom capability of Sony camera DSC-H 10, up to 10)"-"Finally, just smile and do whatever you want.
2. The ancients said, "The Tao is one foot high and the devil is ten feet high." As long as there is a password, there must be a cow who can crack it. It is suggested that the landlord practice hard for ten years, be a cow and pay the electricity bill for us novices. I believe that the landlord will not care about this small electricity bill then.
Note: the landlord said "I don't think it is necessary to find someone to make these cards" should be misunderstood. Cards are mass-produced and can be seen everywhere in the market. There are many people who can design programs, and everyone can encrypt them, but decryption is not so simple. Decrypting them is a far cry from designing these things.