Hacker News: dvwobuq

New comment by dvwobuq in "Working Ternary ALU (2019)"

dvwobuq — Sun, 02 Jul 2023 18:54:07 +0000

Really cool article and I definitely appreciated the section at the end that compared ternary to CMOS.

But in order to use ternary in a real processor, as suggested by the article, we would need a much more formal definition of the voltage levels of the gate.

Something like this: https://www.egr.msu.edu/classes/ece410/mason/files/Ch7.pdf

Without that it’s not clear how one could do timing analysis or do dynamic gate resizing to deal with practical issues like fanout.

Also, without the more formal definition it’s not even clear, to me anyway, what figures like 22 are even measuring.

New comment by dvwobuq in "Video: Power LED Attack [video]"

dvwobuq — Sun, 02 Jul 2023 17:27:41 +0000

It's a harder EE problem than you think. For example the Samsung Galaxy S8 was attacked by analyzing video footage of the power LED of Logitech Z120 USB speakers. Those were most certainly on a different power supply and the two were connected by a long wire.

There are circuit level solutions but the solution is not a $0.01 MLCC.

And once you solve the LED problem remember: The S8 was attacked by plugging in a peripheral to it’s 5V USB supply. Imagine if the peripheral was instead a high speed ADC that just measured 5V USB directly…

New comment by dvwobuq in "Video: Power LED Attack [video]"

dvwobuq — Sun, 02 Jul 2023 17:23:41 +0000

> I could construct a "bench level test" that MIGHT be able to detect the computation

No need. The author of the original paper already did that for you. https://eprint.iacr.org/2023/923

"We demonstrate the application of video-based cryptanalysis by performing two side-channel cryptanalytic timing attacks and recover: (1) a 256- bit ECDSA key from a smart card by analyzing video footage of the power LED of a smart card reader via a hijacked Internet-connected security camera located 16 meters away from the smart card reader, and (2) a 378-bit SIKE key from a Samsung Galaxy S8 by analyzing video footage of the power LED of Logitech Z120 USB speakers that were connected to the same USB hub (that was used to charge the Galaxy S8) via an iPhone 13 Pro Max."

To all the EEs out there. PSRR and power supply cross talk is a thing...

New comment by dvwobuq in "Intelligent people take longer to solve hard problems: study"

dvwobuq — Thu, 22 Jun 2023 20:30:31 +0000

I can entirely relate to this.

About three weeks into my first undergraduate class on abstract algebra, it dawned on me that the instructor wasn't giving me math tests. He was giving me vocabulary tests. In that class, most of the answers to questions flow straight from the definitions. Once I broke out the flashcards and started memorizing definitions, that class became almost trivial.

I used flashcards in all my classes after that to memorize terms, definitions, and concepts. Math and engineering are, for me anyway, like a foreign language. To converse in that language fluently, one must be very comfortable with the vocabulary. It just makes sense.

New comment by dvwobuq in "The legend of “x86 CPUs decode instructions into RISC form internally” (2020)"

dvwobuq — Sun, 18 Jun 2023 22:34:07 +0000

Patterson and Waterman detail exactly what they we’re thinking during the design of RISCV in the RISCV Reader and Cray is mentioned in multiple places.

https://www.goodreads.com/en/book/show/36604301

New comment by dvwobuq in "Tech's Reckoning"

dvwobuq — Sat, 17 Jun 2023 20:17:25 +0000

2023, when a rocket landing backwards and being reused is blasé. :)

New comment by dvwobuq in "Tech's Reckoning"

dvwobuq — Sat, 17 Jun 2023 20:02:38 +0000

What’s tech? I recently had surgery and the surgeon used a robot. I was an out patient the same day and had basically no pain without medication. Compared to a similar surgery I had roughly twenty years ago this experience was like science fiction. Does that count?

New comment by dvwobuq in "Basics of Proofs (2017) [pdf]"

dvwobuq — Sat, 17 Jun 2023 19:49:23 +0000

That’s interesting. In your context what is “knowing the answer”? To me it seems like they “knew” a given statement was true but they didn’t know how to prove it which makes me wonder how they knew.

New comment by dvwobuq in "Apple unveils new Mac Studio and brings Apple Silicon to Mac Pro"

dvwobuq — Mon, 05 Jun 2023 19:22:20 +0000

Bad news everyone, modeless isn't buying one. On the other hand I look forward to the steep discounts to be had at Apple's going out of business sale...

New comment by dvwobuq in "Apple Vision Pro: Apple’s first spatial computer"

dvwobuq — Mon, 05 Jun 2023 19:17:49 +0000

> Some say $3499 is a high price

As a golfer I can assure you plenty of people will happily spend that amount and more on their hobby.