3 ms·

The user friendly option would be to print the amount of RAM in very large letters on the PCB. There happens to be a lot of suitable surface on the PCB to the r

by Tepix 12d ago

The user friendly option would be to print the amount of RAM in very large letters on the PCB. There happens to be a lot of suitable surface on the PCB to the right of the text "Raspberry Pi 5" on the PCB anyway (§). Right now the amount of RAM is hard to read and easy to modify (move a little tiny SMD resistor). Drawback: You need different silkscreens for different amounts of RAM. Btw, if you're worried about RAM-swapped units you can already verify them as described at https://geekworm.com/blogs/news/prevent-ram-swapped-raspberry-pi-5-how-to-verify-factory-ram-size https://geekworm.com/blogs/news/prevent-ram-swapped-raspberr... -- (§) as can be seen here https://pip-assets.raspberrypi.com/categories/1129-pcn/documents/RP-006041-PC-2-PCN%20Raspberry%20Pi%205B%20Rev%204.pdf https://pip-assets.raspberrypi.com/categories/1129-pcn/docum...

kiicia 12d ago
it can be very easily done by burning it with laser on prepared blank box on silkscreen - even iPhones are marked this way with their own serial numbers the only reason why pis are not marked this way is because raspberry didn't wanted to (so far)
buildsjets 12d ago
A little bit of acetone and a q-tip will remove the silkscreen, and then the PCB can easily re-marked by the scammer. Having a new silkscreen made is pocket change.
- jackyinger 12d ago
  Etch it in the top layer of copper, cover it with soldermask. A bit harder to see, but harder to tamper.
  - hasperdi 12d ago
    That's still trivial to defeat. They're very capable and determined. In the olden days they used to mill the top of microprocessor ie intel x86 to remove the engraving and engrave the fake label. These days I imagine it's way more advanced
    - unrented7977 12d ago
      That is in no way trivial.
  - brookst 12d ago
    Put a sticker over it. Sure, the PCB says 2GB, the sticker says 8GB, it was sold as 8GB, how many buyers are going to dig in and really understand what's going on?
nomel 12d ago
No, this is not sufficient, since it would still allow you to swap to shite ram of the same size. This is an age-old problem for counterfeits. The ink on the chip/PCB isn't worth anything. The only way to actually catch this is to do a IQC that runs a full RAM test and hope that if you can't see a difference in performance (throughput, BER, timings, etc), then the chip is correct, with a bit of periodic de-lidding for anything suspicious/sampled. Then, if you can afford it, you blacklist the vendors that are caught changing things. They also added a bit of internal ink, which is worth just a little more: > we now also program in some other device attributes, meaning that switching parts of the same size may not work. Working with vendors in China is entirely adversarial (mostly because their supply chain is vulnerable too), at this scale.

by Tepix 12d ago

kiicia 12d ago

it can be very easily done by burning it with laser on prepared blank box on silkscreen - even iPhones are marked this way with their own serial numbers the only reason why pis are not marked this way is because raspberry didn't wanted to (so far)

buildsjets 12d ago

A little bit of acetone and a q-tip will remove the silkscreen, and then the PCB can easily re-marked by the scammer. Having a new silkscreen made is pocket change.

jackyinger 12d ago
Etch it in the top layer of copper, cover it with soldermask. A bit harder to see, but harder to tamper.
- hasperdi 12d ago
  That's still trivial to defeat. They're very capable and determined. In the olden days they used to mill the top of microprocessor ie intel x86 to remove the engraving and engrave the fake label. These days I imagine it's way more advanced
  - unrented7977 12d ago
    That is in no way trivial.
- brookst 12d ago
  Put a sticker over it. Sure, the PCB says 2GB, the sticker says 8GB, it was sold as 8GB, how many buyers are going to dig in and really understand what's going on?

nomel 12d ago

No, this is not sufficient, since it would still allow you to swap to shite ram of the same size. This is an age-old problem for counterfeits. The ink on the chip/PCB isn't worth anything. The only way to actually catch this is to do a IQC that runs a full RAM test and hope that if you can't see a difference in performance (throughput, BER, timings, etc), then the chip is correct, with a bit of periodic de-lidding for anything suspicious/sampled. Then, if you can afford it, you blacklist the vendors that are caught changing things. They also added a bit of internal ink, which is worth just a little more: > we now also program in some other device attributes, meaning that switching parts of the same size may not work. Working with vendors in China is entirely adversarial (mostly because their supply chain is vulnerable too), at this scale.