cryptage eeprom

[RAYMON]

hi

I have an electronic base map of a microcontroller and an external EEPROM, the program that I use terminal that uses the usb port of the PC, which I use a view data in memory and also has erased.


Or maybe the data is compressed in the eeprom and how to decompress?
My problem is that the data is encrypted, I think they are stored in the eeprom to clear, and the microcontroller will encrypt before sending them to the PC.

An example:

ª ª ª öñ? Vu @? _ ª OQ? A? 5? ÖñûkeÒÅLÝ / 7á_Yn_. | 7M (^ F69) oa / n)
L1) | 7! _n (. N | `© M ÖñÏkRÒF.JMW8 (4puo" 2v) e. <x?a.> x? G *: E ~) R | nN
\ | NL2 "
Z_õQ? LiX,
ZNkX
. ZLiX, jmZzjJkf
(niZDht5D ~ RH0f `lr/dzpH4 + DzVR3XDTJ) DxVPlDjJ / D ~ hPlDlJ) DxVRf_õQ - @` BZT TH6 + \-Nbhtd @ V ^ / JbVvbBVZlnVp-dlv | 2XB ^ tXHzt4XB \ tNDR | 2FB ^ tJDRFjjzX-`pxX29JjxZ23XJzt83_õQ?) RjzZVjfDVtfFHÿÿÿÿÿÿÿÿÿÿÿÿÿÿ ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ

To clear the text:

1212131323323434 = 45454556567878989890
I can use the program and save the data as I wish the problem is receiving data which are encrypted.
And changes for each reading the same text, the reading will always be different?

Thank you for your help

[RAYMON]

hi

I have an electronic base map of a microcontroller and an external EEPROM, the program that I use terminal that uses the usb port of the PC, which I use a view data in memory and also has erased.


Or maybe the data is compressed in the eeprom and how to decompress?
My problem is that the data is encrypted, I think they are stored in the eeprom to clear, and the microcontroller will encrypt before sending them to the PC.

An example:

ª ª ª öñ? Vu @? _ ª OQ? A? 5? ÖñûkeÒÅLÝ / 7á_Yn_. | 7M (^ F69) oa / n)
L1) | 7! _n (. N | `© M ÖñÏkRÒF.JMW8 (4puo" 2v) e. <x?a.> x? G *: E ~) R | nN \ | NL2 " Z_

õQ? LiX, ZNkX . ZLiX, jmZzjJkf (niZDht5D ~ RH0f `lr/dzpH4 + DzVR3XDTJ) DxVPlDjJ / D ~ hPlDlJ) DxVRf_

õQ - @` BZT TH6 + \-Nbhtd @ V ^ / JbVvbBVZlnVp-dlv | 2XB ^ tXHzt4XB \ tNDR | 2FB ^ tJDRFjjzX-`pxX29JjxZ23XJzt83_

õQ?) RjzZVjfDVtfFHÿÿÿÿÿÿÿÿÿÿÿÿÿÿ

To clear the text:

1212131323323434 = 45454556567878989890
I can use the program and save the data as I wish the problem is receiving data which are encrypted.
And changes for each reading the same text, the reading will always be different?

Thank you for your help[/QUOTE]

[RAYMON]

Or maybe the data is compressed in the eeprom and how to decompress?
My problem is that the data is encrypted, I think they are stored in the eeprom to clear, and the microcontroller will encrypt before sending them to the PC.

[mister_e]

Is ...

ª ª ª öñ? Vu @? _ ª OQ? A? 5? ÖñûkeÒÅLÝ / 7á_Yn_. | 7M (^ F69) oa / n)
L1) | 7! _n (. N | `© M ÖñÏkRÒF.JMW8 (4puo" 2v) e. x? G *: E ~) R | nN
\ | NL2 "
Z_õQ? LiX,
ZNkX
. ZLiX, jmZzjJkf
(niZDht5D ~ RH0f `lr/dzpH4 + DzVR3XDTJ) DxVPlDjJ / D ~ hPlDlJ) DxVRf_õQ - @` BZT TH6 + \-Nbhtd @ V ^ / JbVvbBVZlnVp-dlv | 2XB ^ tXHzt4XB \ tNDR | 2FB ^ tJDRFjjzX-`pxX29JjxZ23XJzt83_õQ?) RjzZVjfDVtfFHÿÿÿÿÿÿÿÿÿÿÿÿÿÿ ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ


the data you see on Hyperterminal? If so, well yes it could be all sort of thing, looks like a bad baudrate setting to me at first.

Did you tried a COM port sniffer to see how things are going between the PC application and the target board? A COM port sniffer also tell you the baudrate. I remember having few application which used weird baudrate and sometimes they changed from one baudrate to another baudrate value as well.

If you don't have access to any source code, that will be tough...

[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/showthread.php?t=2813&highlight=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