Mycelium Entropy update

[cetus]

I heard the last batch had just arrived at Mycelium office in Vienna for flashing and final assembly.

[1714109854]

1714109854

[1714109854]

1714109854

[cisary]

I'm waiting for mine too.. Is there a way to modify the firmware so that I can use Entropy as HW random number generator? I want to print bunch of wallets and then I plan to experiment with code.. open source FTW!

When did you order?

In the beginning of March shortly before there was "first batch sold out.." announcement

[cetus]

I'm waiting for mine too.. Is there a way to modify the firmware so that I can use Entropy as HW random number generator?

Yes, but there is a nuance.

The main hardware entropy source (SRAM) works only once when you power it up.  If you want to generate a continuous stream, you have to use the built-in TRNG (probably safe, as it's not from Intel) and ADC measurements of a floating input.  There is a new appendix in the user manual about it: https://mycelium.com/assets/entropy/me.html#_appendix_b_how_it_works .

You can power SRAM off in hibernate mode, but it takes about 30 seconds for each sampling of about 6 kbits of entropy.  SRAM discharge is slower in hibernate mode than when the device is unplugged.

Personally, I doubt there is any chance at all that Atmel's built-in hardware RNG is compromised.  And you can still use the one-off salt from SRAM to thwart any hardware attacks on the built-in TRNG module.

[Rassah]

FYI, the first batch of 800 devices sold out around August. So anyone ordering in September onwards had to wait. Yes, the remaining 200 were received recently, and are being packaged and prepared for shipping now.

[ZorroPai]

Hi,
I am living in Vienna and would like to buy an Entropy-Device cash.

Can I come to you tomorrow?

Thank you,
Zorro

[trasla]

Hi,
I am living in Vienna and would like to buy an Entropy-Device cash.

Can I come to you tomorrow?

Thank you,
Zorro

Hey, sorry for the late answer.
We still have a couple open to ship, which I send out as I get them from the hardware department - so no spare ones to sell, currently.
I could maybe borrow you mine, if you just want to make a couple of paper wallets, though.
Shoot me a PM if you would like to!

[dsattler]

If someone wants to verify the 2-of-3 private key shares that entropy prints, here's a way to do it:

• Download the sss python code from here:
  https://github.com/cetuscetus/btctool/blob/bip/bip-xxxx.mediawiki
  
  
• Download the bitcoin address utility (windows exe or source) from here:
  https://casascius.wordpress.com/2013/01/26/bitcoin-address-utility/
  
  
• NOW IT'S A GOOD TIME TO GO OFFLINE, BECAUSE THE NEXT STEPS COULD OTHERWISE COMPROMISE YOUR PRIVATE KEY!!! 
  
  
• Edit the test() function in bip-sss.py like this:
  

  def test():
      gf = GF(0x11d)
  
      share1, dec_m1, dec_id1, dec_type1 = decode("SSS-<enter your entropy private key share 1 of 3 here>")
      share2, dec_m2, dec_id2, dec_type2 = decode("SSS-<enter your entropy private key share 2 of 3 here>")
      share3, dec_m3, dec_id3, dec_type3 = decode("SSS-<enter your entropy private key share 3 of 3 here>")
     
      shares = [ share1, share2, share3 ]
  
      combined = combine(gf, shares)
      secret = make_secret(CTB_BASE58, length = 32, data = combined[1:33], is_private_key = True, compressed = True)
  
      #sss_test(gf, 1, 1)
      #sss_test(gf, 2, 1)
      #sss_test(gf, 1, 2)
      #sss_test(gf, random.randint(1, 64), random.randint(1, 255))
      #sss_test(gf, random.randint(1, 64), random.randint(1, 255))
      #sss_test(gf, random.randint(1, 64), random.randint(1, 255))
  
      #enc_dec_test(gf, 20)
  

  Put the three shares ("SSS-...") from your entropy printout into the script!
  
  
• Go to the end of bip-sss.py, uncomment test() and comment gen_vectors():
  

  test()
  #gen_vectors()
  

  
  
• Run the script, it will output your private key in WIF format (or an error if something's wrong with your shares).
  I'm using ubuntu in a VirtualBox on windows for that.
  If you're not familiar with python scripts (like myself  ) it's better to run it once without any modifications (it prints out some tests), to see if everything is in place and working OK.
  
  
• Run the bitcoin address utility, navigate to menu tools/utility and enter your private key (from the python script) into the field labeled "Private Key (WIF)".
  Click on the second button under the input field (with two triangles pointing down).
  Your BTC address is shown in the last field, compare it with the printout.
  Should be exactly the same if everything went OK! 
  

I hope that this description is somehow useful. Don't hesitate to ask me if something's unclear.

For total security I recommend to do this procedure on a disconnected PC which never touches the internet.
If you do this on a PC which is infected with malware (trojans, keyloggers, etc.), your private key could get stolen and your BTC will be lost!