CRC and ATECC608A-SSHDA

Go To Last Post
3 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0


  Hi there

 

  I am trying to figure out how ATECC608A handles the CRC. I do not have yet datasheet for ATECC608A-SSHDA, I do have for ATECC508A and ATECC608A-TNGTLS. Both these two datasheets describe the same functionality regarding CRC.

 

  I started to test with the simplest command, Info. For start, I built the I2C packet and for CRC I did calculated with online calculator just to test. It did not work. Out of solution, I made a loop and tested all 65536 possible values. After about 21 minutes I got a match. However, I cant' get any online calculators to get the same value. When the CRC is correct, it replies with data requested. Here is what it works:

 

send command:

 

receive from ATECC608A - last two bytes are CRC

 

  I did try online calculators:

https://www.lammertbies.nl/comm/...

https://crccalc.com/

 

  What could be the problem ?

  Thank you.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

angelu wrote:
  What could be the problem ?

Well for one, its not a CRC!  But further discussion of crypto on an open forum may be prohibited!   cheeky

 

(Possum Lodge oath) Quando omni flunkus, moritati.

"I thought growing old would take longer"

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Forum for Atmel's security products / topics:

 

https://community.atmel.com/forums/general-security-discussions

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...