Insulin Pumps, Decapped Chips and Software Defined Radios

Insulin Pumps, Decapped chips and Software Defined Radios
Reverse Engineering an Insulin Pump for DIY Closed Loop Therapy
Roughly 3 years ago, I heard about a website offering a bounty for something that was very close to my heart: reverse engineering communications to an insulin pump. Months passed with little progress, and finally in winter of 2016 a member of the group with the handle @lorelai posted that she had sucessfully dumped the firmware from the larger ARM-based chip on the PDM, and started the tedious process of disassembly: taking cpu instructions and turning them into human understandable code with semantic variable and function names. We started working on decoding messages, recording sessions from the PDM for delivering boluses, temp basals, suspends, etc…
Nonce
All of the insulin delivery commands had a 4-byte chunk of data near the beginning of the message that looked like it might be some form of cryptography.

Source: blog.usejournal.com