| ??? 05/04/05 17:29 Read: times |
#92907 - Now i understand! Responding to: ???'s previous message |
Thanks Erik, and Jan,
I realize now that i need a parallel programmer, I am sorry, how is it possible to change ISP, when ISP is running (not experienced) but concerns that it is possible to write own custom ISP and then when the code is placed into the flash, then use decryption. Ofcourse one has to make its own FM. So now I am busy on writing the ISP code which can be used to decrypt the encrypted data. The reason why ENcryption(to ERIK), the application has to be updateable, and the customers could be anywhere over the world, sending the device to us is not an option, just updating by Internet will be the option. I am busy with making my own software which takes the HEX record file, scrambles it. ANd then i am going to make my own FM program and send the scrambled data to the device. The device can be put into update mode using INT1 button hold on powerup. There it can evantually communicate trough UART and decrypts the scrambled code back to original code and after it places the records into RAM and then the IAP program_user_code is called. for security i even used Eriks notouch() method to backdoor the ISP for safty. It is very simple method,. BUT i think that using the ISP-encryption is the best method as it is easier but more help is needed from the masters ;) so i am working on both methods, ISP encryption, and making own update-encryption routine with in my program. best regards, Khaled |
| Topic | Author | Date |
| ISP-AES(or other tiny encryption)for LPC | 01/01/70 00:00 | |
| so it works? | 01/01/70 00:00 | |
| re so it works? | 01/01/70 00:00 | |
| could it be | 01/01/70 00:00 | |
| TEA | 01/01/70 00:00 | |
| re could it be? | 01/01/70 00:00 | |
| double-xor | 01/01/70 00:00 | |
| LPC935 | 01/01/70 00:00 | |
| TEA | 01/01/70 00:00 | |
| Tea time! | 01/01/70 00:00 | |
| TEA time ;) | 01/01/70 00:00 | |
More tea | 01/01/70 00:00 | |
| Please clarify requirements | 01/01/70 00:00 | |
| what i want, Dan | 01/01/70 00:00 | |
| Looks like you are set then | 01/01/70 00:00 | |
| to Dan | 01/01/70 00:00 | |
| Re: to Dan | 01/01/70 00:00 | |
| Mode of operation | 01/01/70 00:00 | |
| I underdstand now., thanks | 01/01/70 00:00 | |
| better done in hardware | 01/01/70 00:00 | |
| what about this? | 01/01/70 00:00 | |
| what are you making | 01/01/70 00:00 | |
| theft has to be prevented | 01/01/70 00:00 | |
| either or | 01/01/70 00:00 | |
| FM is just a "vehicle"... | 01/01/70 00:00 | |
| but a diesel | 01/01/70 00:00 | |
| it's easy | 01/01/70 00:00 | |
| again, why | 01/01/70 00:00 | |
| unsecure? | 01/01/70 00:00 | |
| yes | 01/01/70 00:00 | |
| Individual sector security bits removal | 01/01/70 00:00 | |
| lockbits | 01/01/70 00:00 | |
| Now i understand! | 01/01/70 00:00 | |
| same thing | 01/01/70 00:00 | |
| what am i making? | 01/01/70 00:00 | |
| be careful | 01/01/70 00:00 | |
| why GSM? | 01/01/70 00:00 | |
| FM | 01/01/70 00:00 | |
| FM | 01/01/70 00:00 | |
| for the xor method to work | 01/01/70 00:00 | |
| RC4 | 01/01/70 00:00 | |
| RC4 | 01/01/70 00:00 | |
| A reminder | 01/01/70 00:00 | |
| encryption | 01/01/70 00:00 | |
| pgpi.org | 01/01/70 00:00 | |
| ok thanks jez | 01/01/70 00:00 |