A Simple explanation of what is a TPM device (ISO/IEC 11889)

On Receivers from the manufacturers VU+, DM and most of the electronics today, there is "firewalls" inside to prevent the installation of wrong software that could get your hardware during an upgrade/update of the internal software, to fail.

These components have different physical forms, like SMD chips directly soldered into the motherboards, or even plastic cards (cut in different sizes like 2FF, 3FF, etc as called commonly Sim, due to the ISO7816 Specifications).

These components have inside a software that will check with a cryptography process, if the software update you will load is compatible with the previous version and if the software is built for the hardware you intent to install it to.

Generally manufacturers are using built-in hardware cryptographic algos in their TPM chips such as RSA or AES with Public and Private Keys. This is the case for the VU+ / DM manufacturers.

You can easily see on the photo below the chip, or the drawing of the plastic chip in physical "2FF Sim plastic" card Holder.



You can see on the photo below, the TPM Chip in physical form of 2FF/Sim, below of the smartcard reader where is the HDD support (Bottom left of the photo below).



This device is called TPM, and you can read more on how if function on the internet, Wikipedia or technical publishings explaining how it works and why it was implemented on mostly all electronics we have today. Software is never "finished" and never bug free, so it was necessary to allow the update of the hardware and the TPM solution was the only one preventing the failure of the update and the error of loading a wrong update into the wrong hardware.

Today, due to the planned obsolescence by some manufacturers that stop support of their hardware, passionate people like us want still to use their hardware they bought and doesn't want to waste it and create more garbadge to the planet. So we continue supporting and doing new software updated with bug fixes, security features (like SSH Bug fixes), etc to prevent the end of life of what we bought, and allow them to work until the last day these can be used.

All the TPM/Sim devices named A8P/A4P/A2P/Sim2/Ferrari/Japhar are TPM devices, in different form factors (Chip/MFF2 or 2FF).

1FF Full Size 85.6 x 53.98 x 0.76
2FF Mini SIM Standard SIM 25 x 15 x 0.76
3FF Micro SIM 15 x 12 x 0.76
4FF Nano SIM 12.3 x 8.8 x 0.67
MFF2 Embedded SIM eUICC SON-8 IC Footprint 6 x 5

So if you have any question to understand more this, we would be happy to explain you.

References :
- Wikipedia TPM (ISO/IEC 11889)
https://en.wikipedia.org/wiki/Trusted_Platform_Module

- Microsoft
https://docs.microsoft.com/en-us/windows...module-overview

- ASUS
https://www.digitec.ch/en/s1/product/asu...essories-374265

and here you can understand more about what is a TPM... Trusted Platform Modules are poorly understood by many, well understood by few.

https://www.iotworldtoday.com/2019/02/07/trusted-platform-modules-8-surprises-for-iot-security/

- What is a TPM ?
https://www.laptopmag.com/articles/tpm-chip-faq