cryptage eeprom

[RAYMON]

Hi

No it is not a setting, the Terminal program fontionne well, and the data received
are encrypted or compressed?

Here is a second example
-------------------------
The is OK

O N M L K J I F E B
= = = = = = = = = =
1 2 3 4 5 6 7 8 9 0
--------------------------



10 BYTES

A5 0A 4F 4E 4D 4B 4A 49 47 46 45 42
¥. O N M L K J I F E B

--------------------------------------
2 BYTES

A5 02 4C 48
¥. L H

-------------------------------
3 BYTES

¥. L H D
A5 03 4C 48 44

-------------------------------
1 OCTET

A5 01 4A
¥. J
-------------------------------
5 BYTES

¥. M I I J J
-------------------------------

[Melanie]

Raymon, what you are posting is totally meaningless. Asking Bletchley Park (see Google) is perhaps a better option for you.

You could be looking at Data, you could be looking at Machine Code, you could be looking at a combination of both, it may be encrypted, it might not be. It may be compressed, it might not be. It might be combinations of everything.

For example, you could be looking at the interchange of Data between a Smart-Card and an ATM terminal, or between a Smart-Card and a TV Subscription Receiver.

There are hundreds of different encryption systems around the world, and hundreds of different compression alogrythms... without knowing which one, and without knowing what HARDWARE is involved (because if there is any embedded Machine Code it will be different for each family of chips), and without knowing the APPLICATION CONCERNED, it is a COMPLETE WASTE OF TIME.

And, if it is encrypted Data, you are obviously trying to gain access to something that you are not supposed to. In effect you could be asking this forum to help you commit Copyright or other Intellectual Property theft. The guy that cracked the code for Series 7 of the Sky Satellite Card got 4 years jail! Let's not put this forum or any contributor to it in that position.

[RAYMON]

Hello

This is an electronic circuit of a base pic 16F876 and I looking for information
and understand how to have protected EEPROM?
is it possible to protect against the reading for the pics?
this example and decryption I put on the site is to give an idea.

http://www.picbasic.co.uk/forum/show...ighlight=ascii

[jonas2]

At the first start-up, you generate a table of random byte in Flash. And you do a XOR between the data write (read) and the table. You can complicate making an XOR between the EEPROM and the address table