[chants]

Interesting article on a real world example:

https://www.wired.com/story/unciphered-ironkey-password-cracking-bitcoin/

To fully reverse engineer the device, Unciphered scanned an IronKey with a CT scanner, then began the elaborate surgery necessary to deconstruct it. Using a precise laser cutting tool, they carved out the Atmel chip that serves as the USB stick's “secure enclave” holding its cryptographic secrets. They bathed that chip in nitric acid to “decap” it, removing the layers of epoxy designed to prevent tampering. They then began to polish down the chip, layer by layer, with an abrasive silica solution and a tiny spinning felt pad, removing a fraction of a micron of material from its surface at a time, taking photos of each layer with either optical microscopes or scanning electron microscopes, and repeating the process until they could build a full 3D model of the processor.

Because the chip's read-only memory, or ROM, is built into the layout of its physical wiring for better efficiency, Unciphered's visual model gave it a head start toward deciphering much of the logic of the IronKey's cryptographic algorithm. But the team went much further, attaching tenth-of-a-millimeter gauge wires to the secure element’s connections to “wiretap” the communications going into and out of it. They even tracked down engineers who had worked on the Atmel chip and another microcontroller in the IronKey that dated back to the 1990s to quiz them for details about the hardware. ...

That cracking process culminated in July, when Unciphered's team gathered at an Airbnb in San Francisco. They describe standing around a table covered with millions of dollars’ worth of lab equipment when a member of the team read out the contents of a decrypted IronKey for the first time.