| ??? 05/04/05 08:01 Read: times |
#92864 - double-xor Responding to: ???'s previous message |
Khaled,
This is perfectly valid; if you xor both the received character and the transmitted character by the same number, you get echoed back the original character. However, the bootloader itself should not work. E.g. it should not respond on the :00000001FF command (while the original bootloader should). But why did you abandon the way you started - to encrypt (first xor) only the byte to be programmed - that is the way you should proceed, I believe. Btw. are you sure you are downloading and running the CHANGED bootloader? I hope you have some means to program the chip using ICP or a parallel programmer - if you succeed to modify the bootloader in any way, you sill not be able to use FM any more. And what is your hardware? On flashmagic forum, you mentioned you are using LPC936, while here you say you are using the bootloader for LPC935; they have different amount of FLASH and also different bootloader entry point; are you aware of that? Jan Waclawek |
| 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 |