Basically one word to the cards. These cards are no season tickets! The club Dynamo Dresden make them to what they should be. I have only the pure cards! They are personalized at Dynamo Dresden and there the cards get their datas. No unauthorized people can have access to the datas.
The cards do have a memory of 1KByte. Two different passwords are there to protect the contents. Without those keys you do not have any access to the contents. In a "virgin" card that's different. They are equipped with a so-called transport code, that is well known and is "FF FF FF FF FF FF". These transport codes can be overridden with new specific passwords, if required. My application does not need specific security requirements, so I will use the card exclusively with the transport code.
Additionally to the two possible passwords each card has its own "ID", the UID Number (UID = U nique ID entification). This consists of four bytes and a check sum. Since it is stored on a card in binary, it is in its present form not reasonable to use. So either I will use in the UID in HEX numbers or decimal values. I opted for the decimal version. So I have 4 numbers in between the number range of 0-255. Among the four numerical UID values the check value will still join, which also will be read out. Here is an example of an RFID card UID: 254 72 152 209 255 .
Such digits sequences will meet us again in the future.
