Ok, since Phillymatt is such a fan of facts, I did a little research on self destruct circuitry.
There are several ways to implement this in a circuit design.
- Physically Unclonable Function (PUF) Chips
- These chips generate a unique “fingerprint” based on inherent physical variations. Some designs include self-destruct mechanisms that trigger when tampering is detected—such as probing or voltage anomalies.
- Circuit Suicide Techniques
- Researchers have developed chips that destroy themselves by manipulating voltage across encryption key circuits. These methods can be triggered by unauthorized access attempts or environmental changes like temperature spikes
- DARPA-Inspired Self Destructing Chips
- A chip showcased at the DARPA Technology Forum can disintegrate within seconds when triggered. This is aimed at military and sensitive data applications, and uses materials that rapidly degrade under specific conditions.
- Timeout-Based Destruction
- experimental designs include aging-based self-destruction, where the chip disables itself after a set operational period or when exposed to certain environmental stressors like heat or voltage shifts.
I think #4 is what Matt is alluding to. So I looked more into those. Especially since I don't think anyone was using DARPA chips in consumer electronics. The BOM costs would astronomical.
These are currently in very limited, or experimental production.
There's an Aging-triggered chip developed by the University of Vermont in tandem with Marvell Technologies (a supplier I'm familiar with).
- These chips exploit natural aging, temperature variation, and voltage stress to trigger self-destruction.
In Summary:
These chips are NOT commercially available today, let alone in the 80s and 90s when Matt was in his career heyday.
SO! I asked AI, how would a self-destruct circuit be built with late 1980s electronics and technology.
- Components to Use:
Timing: RC circuits, 555 timer, NE555 or LM555
Logic Control: TTL or CMOS logic gates, 74LS series or 4000 series
Power Switching: Transistors or relays, 2N2222, TIP120, Reed relays
Destruction Trigger (oooo): Fuses, burn-out resistors, SCRs, 1A glass fuse, MCR100-6 SCR
- Timeout Mechanism:
Use a
555 timer in monostable mode to create a delay:
Configure it to output HIGH for a set time (e.g., 10 minutes).
After timeout, output goes LOW, triggering the destruction circuit.
Alternatively, use an
RC delay with a comparator (e.g., LM339) to detect when voltage drops below a threshold.
- Self Destruct Mechanism
After the set timeout, trigger one of the following:
Blow a fuse: Use a transistor or SCR to send high current through a fuse.
Corrupt a memory chip: Apply reverse voltage or overcurrent to a small EEPROM or SRAM.
Cut power: Use a relay to disconnect Vcc from the rest of the circuit.
Example Circuit Flow:
- Power ON → 555 timer starts countdown.
- During countdown → circuit operates normally.
- After timeout → 555 output LOW → triggers transistor → sends current through fuse → fuse blows → circuit disabled.
PhillyMatt, were you able to identify these workflows or similar layouts in all the self-destruct circuitry you identified in all those years of experience?
Edit1: I can tell you right now, some of the products I've worked on in design, we barely, BARELY were able to fit all the electronics and circuitry we needed in the layouts and housings, while still functioning as we needed. Packaging is crazy tight, even with modern technology. To add all that self destruct circuit space, AND BOM costs! It would be a non-starter.
The cheapest and easiest way to "time out" a product would to just value engineer and cost cut the existing components, knowing with validation testing, they would fail after a typical # of years.
Edit2: Post-post, I found a blog on Marvell's site discussing self-destruct chips they're working on (now, not 20yrs ago)
https://www.marvell.com/blogs/self-...d-static-and-dynamic-entropy-in-one-chip.html
