How to "open" a microchip and what's inside?

http://zeptobars.ru/en/read/how-to-open-microchip-asic-what-inside

by networked • 13 years ago

209 46 13 years ago

networked• 13 years ago

I've got to add that this is pretty much how Intel's x86 processors were reverse engineered [1] for use in Soviet IBM PC clones like Poisk [2]. Most resources on the Web talk about clones of CPUs up to and including the 80286 but I am told there was at least one successful attempt at cloning an earlier version of the 80386. The smaller sub-1 µm process used by Intel for later 80386 and 80486 units proved too much, however.

[1] http://www.cpu-world.com/info/exUSSR-chips.html

[2] http://www.oldcomputermuseum.com/poisk.html

jgw• 13 years ago

It's pretty much how modern ASICs are reverse-engineered today - mainly for patent infringement investigation.

smalley3• 13 years ago

There are actually substantially more steps involved in reverse engineering more modern SOCs. After depackaging the chips you have to strip the metal layers, special protective layers etc to get to the base layers. Modern processes can have upwards of 8 metal layers along with a top layer composed of filled metal (there are issues with processing if a relatively uniform amount of metal isn't on each layer).

After you get the images of the metal layers (you likely can't do this optically for things down near Metal1) you can image the poly and diffusions. You can probably guess which transistors are which based on which power rails they would have been connected to.

Things might be easier if you know what standard cell library the designers used when laying out the chip, as then you'd more easily be able to identify the base logical functions faster.

If you're being thorough you'd also have to make sure you obtain measurements of the widths of each of the transistors (so you can later figure out the relative drive strength which matters for things like identifying keeper circuits or more precision analog elements etc).

Determining some transistor behavior make require even more complicated tests to identify doping levels and if you were trying to duplicate the process you'd have to identify a large number of other materials (for example if they use copper you'd want to find what chemical they used to control the diffusion etc).

It's pretty interesting stuff though.

BarsMonster8• 13 years ago

I am the one who have done all these chip photos.

I am still looking to find soviet 286 (КР1847ВМ286), but it seems it is extremely rare. If anyone have one - contact me ASAP :-)

Just to be fair - I didn't find that soviet "clones" were clones - layout was changed significantly. Centralized planning demanded 100% compatible chips to make near-100% compatible computers, that's the root of all evils.

terminus• 13 years ago

Thanks for all the work. That was an amazing read.

I've always wondered how people map chip-die photos into something like this: http://chip-architect.com/news/2007_02_19_Various_Images.htm...

or this: http://chip-architect.com/news/2003_09_21_Detailed_Architect...

I can see how figuring out the cache and the internal buses might be doable, but the rest... Any insights?

slug• 13 years ago

Awesome work. A simple suggestion: make clear that the labels point to the right picture, say with a horizontal line separating them, since the description for the next image is right below the one before it.

jfb• 13 years ago

What sort of camera rig did you use? The pictures are lovely.

fnordfnordfnord• 13 years ago

Great work. Did you ever see these? http://micro.magnet.fsu.edu/creatures/pages/russians.html

Also, there are a few collectors over here: http://www.cpu-world.com/forum/

Maybe they can get you a lead on one.

kamaal• 13 years ago

Whoa!

Never knew a microprocessor/microcontroller/ASIC could be reverse engineered.

How do they even tackle such complexity?

Do you know of any resources which explain how it is done?

BarsMonster8• 13 years ago

Check out these videos: http://www.youtube.com/user/Andorianin/videos?view=0&flo...

There is also software for automatic photo->schematics conversion, but this is quite complicated & not something you can buy at store.

subsystem• 13 years ago

This is also how mifare security was reverse engineered and broken. If I remember correctly they sanded down each layer and used image recognition.

https://www.youtube.com/watch?v=QJyxUvMGLr0

LAMike• 13 years ago

It looked like maps from GTA

vxNsr• 13 years ago

Incredibly cool! Thanks for sharing

contingencies• 13 years ago

Even though the details may already be well known, someone with some stock could consider sending these guys a 'clipper chip' in celebration of its defeat. http://en.wikipedia.org/wiki/Clipper_chip

XorNot• 13 years ago

It seems like you could avoid the heating needs as much by using hydrogen peroxide with the sulfuric to make Piranha solution, which is a great and voracious organic compound eater.

BarsMonster8• 13 years ago

Initially I was trying that, but 98% sulfuric acid and 40% hydrogen peroxide needed like 3 days to etch plastic (with like 10 fresh "mixes"). Now I can try that with higher concentrations, would be great if It could lower temperature.

pbhjpbhj• 13 years ago

How did you heat it up, microwave?

Frencil• 13 years ago

Amazing how the insides of these chips are composed of similar looking traces and microcomponents to the PCBs that house them on a larger order of magnitude.

rsingla• 13 years ago

These are just gorgeous.

theoretick• 13 years ago

Beautiful. I think I just found my new desktop background.

frdgr• 13 years ago

Beautiful!! Someone should make large posters out of this.

The process gives it an artsy mechanical feel, as if we could see the sign of time and efforts these little things put in computations.

sciurus• 13 years ago

I don't know about posters, but there is similar imagery in "Core Memory: A Visual Survey of Vintage Computers"

http://www.amazon.com/Core-Memory-Visual-Vintage-Computers/d...

chiph• 13 years ago

Intel used to make posters available (back in the Pentium-II days) and they were really cool. I used to have one that I had to leave behind at a previous job.

In the current copyright environment, I'm not sure they could be made available. Which stinks, as just looking at them & trying to figure out what the sections did (ALU, cache, registers, etc) is sort of inspiring.

Intel, AMD, Freescale, etc. should partner up with art.com or someone else who can print out large posters (and ship them wrinkle-free) Maybe donate any profits to a engineering-for-teens program of some kind.

BarsMonster8• 13 years ago

FYI, I've just switched image hosting to OVH CDN, let me know if images are not loading for you. Thanks.

PanMan• 13 years ago

Which OVH cdn? Did you rent servers, or do they have a cdn service I don't know?

BarsMonster8• 13 years ago

They have CDN service in beta test - http://www.ovh.com/fr/cdn/

tripzilch• 13 years ago

So if I get this correctly from the other comments, reversing a current-day modern CPU chip is much, much harder?

Is it at all possible? On what kind of budget?

Say there's a number hidden on a modern CPU chip, a cryptographic key. That's one of the things "Trusted Computing" architecture uses, right? Is there any way to retrieve that key? With a really large budget? Or is it truly impossible, tamperproof beyond any macroscopic objects, not accessible without destroying the data itself?

Because if that is so, that'd be disgusting, and I understand one of Richard Stallman's paranoid precautions quite a bit better--afaik the netbook he uses has one of the few brands of chips whose design is "open". Of course if it's tiny enough, you still don't know if what's in it is exactly what the design says should be in it (like running binaries instead of compiling from source), but I suppose that is the best one can do.

It's crazy then, that with our drive for faster and faster computers, at some point, we may lock ourselves out.

BarsMonster8• 13 years ago

Everything is possible.

Cloning whole chip is probably economically not viable, but definitely possible (it's cheaper to design from scratch with modern automatic design tools), but retrieving secret keys is a popular task.

For a company having all the tools (electron microscope with bells and whistles, polishing machines, microprobes) it might take hundreds to thousands of human-hours (0.1-1+ million $).

Companies like http://www.chipworks.com/ can do that, if your request is legal.

smalley3• 13 years ago

Absolutely possible, people reverse engineer parts of our chips and I'm pretty sure a well supplied failure analysis lab could do some of the work as well.

It's certainly doable to reverse engineer out a cryptographic key from a chip, but most of the people who could afford to do this wouldn't really need to do so. Secure elements are typically substantially more protected than standard logic. The structures can be designed in a manner to be very difficult to access without damaging them rendering them unreadable.

Such a cryptographic key would likely be scattered in pieces around the chip, delivered through winding busses below enough critical logic connections and power rails so that the chip wouldn't be as vulnerable to a focused ion beam attack or infrared analysis. This makes it difficult to observe without destroying enough of the chip that live examination would not be possible. There are also tricks that would be used to mitigate the risk of differential power attacks etc.

The bigger threats to secure elements are sloppy design with DFT/DFM (Design For Test) features. Most complex chips have at a minimum a mechanism of connecting a large number of the designs flops to what's like a huge shift register. If you knew enough of the design you could try to locate the output of a block which has access to the secure value, scan in a vector that makes it easy to recover the value (e.g. an XOR element you can force to XOR with 0's) and scan it out.

There are also other DFT feature like on-die logic analyzers, micro-breakpoint engines, code signing overrides etc. Virtually all of these features are physically disabled prior to volume manufacturing. If a company was sloppy this could expose things that shouldn't be exposed.

There are other attacks as well though. If you could compromise the signing keys for the microcode delivered to a processor like a modern x86 processor you could change the behavior of instructions. With custom microcode you could catch and override basically any instruction (for example you could change where a LOAD instruction stores data or make ADD do jmp etc). You could definitely use something like that in a malicious manner.

yk• 13 years ago

What is a "focused ion beam attack"? ( Is it as cool as it sounds?)

rdl• 13 years ago

In the public/unclassified world, Flylogic (Chris Tarnovsky)has it down to about 3-6h to extract a key from a moderately protected device (TPM; generally FIPS 140-2 level 3 (physical), using about $1mm in equipment and one guy. This is after years of developing expertise in general, and spending maybe 2-3 months part-time attacking a single model of chip (although within a family, it looks like new models are usually quite similar in layout and protection mechanisms).

Attacking modules instead of chips is a little harder, especially because the modules themselves are more expensive, so expending hundreds of them in early testing is more expensive. But, for a national organization, totally feasible.

If you really want trusted computing, you need defense in depth; the devices need to be in a semi-trusted environment, so a theft/tamper event can be detected, and keys revoked, within the attack window. So, it's ultimately not possible in a feasible way for consumer-possessed devices (trusted computing for DRM); OTOH it works great in a server environment (if someone breaks in, you just invalidate all keys in the facility within a few hours).

HSMs (which have more active tamper response) are a lot better than TPMs (which are purely passive). You could probably trust an HSM even if it falls into enemy hands, unless the enemy is the HSM designer or NSA, for less than $50mm. The problem is there's no decent HSM for less than about $15k now (Thales/SafeNet duopoly). And HSMs have had implementation bugs in the past.

qwertzlcoatl• 13 years ago

Silicon Zoo has some awesome pictures of interesting artwork found on microchips.

http://micro.magnet.fsu.edu/creatures/index.html

StringyBob• 13 years ago

Can't let a post like this go by without name-checking a couple of other sites:

Visual 6502 for taking such photos and then emulating, or should I say simulating, the cpu from the images - in JavaScript: http://visual6502.org/

Chipworks for commercial silicon analysis of big modern system on chips (source of some photos of recent apple silicon): http://www.chipworks.com/blog/technologyblog/2013/01/21/the-...

INTPenis• 13 years ago

What do all the things inside do? Are they like miniature boards with dozens of tiny connections?

ableal• 13 years ago

Basically, yes. Those are silicon chips, with alternate layers of glass (SiO2) and metal deposited on top. The metal layers connect transistors that were built in the silicon chip proper in the first steps of fabrication.

They are called integrated circuits because, instead of using a board to connect many pieces of silicon, a single piece of silicon has the whole circuit. More at the usual place, http://en.wikipedia.org/wiki/Integrated_circuit

dhx• 13 years ago

These images would be a fantastic resource on Wikimedia Commons (for use in Wikipedia articles). The licensing (Creative Commons Attribution 3.0 Unported License) is compatible as per [1] and [2].

I've got things started with the 74HC595 die photo at [3] and [4].

[1] http://zeptobars.ru/en/contacts

[2] https://commons.wikimedia.org/wiki/Commons:Licensing#Well-kn...

[3] http://commons.wikimedia.org/wiki/File:74HC595-HD.jpg

[4] https://en.wikipedia.org/wiki/7400_series

xradionut• 13 years ago

I was having flashbacks to my days and nights spent testing wafers at a semiconductor fab. Spend a shift using a misaligned microscope and walk outside and see THREE moons. But I have mad soldering skills from building probe cards.

mtdev• 13 years ago

More of the same here: http://microblog.routed.net/category/icf/ . Third post contains similar instructions on de-encapsulation.

pg1• 13 years ago

Pretty cool. Thanks for sharing.

How to "open" a microchip and what's inside?

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