* Posts by Bicycle Repair Man

2 posts • joined 26 Jul 2018

Boffin: Dump hardware number generators for encryption and instead look within

Bicycle Repair Man

Interesting effect, wrong explanation

While the code clearly shows a variance in the time, his explanation - that it is caused by variance in the transistors - is BOLLOCKS.

From the article, "CPUs, Roig's paper explains, contain millions or billions of transistors, which have enough variation that no two chips perform identically" This is nonsense. While over-clockers might exploit this to crank a few extra Hz out of their rigs, CPUs are synchronous beasts, so if you run the exact same code on two identical processors, clocked at the same speed, you will get the same result.

The variance will have many sources, from the OS servicing other threads, network interrupts, refreshes on the SDRAM, to caching, but transistor variance is not one of them. If you run this code on a bare-bones processor using on-chip RAM, then I would be extremely concerned if this showed any variance at all.

Ironically, a HWRNG possibly does use transistor variances to guarantee no two generators follow the same sequence...

HPE supercomputer is still crunching numbers in space after 340 days

Bicycle Repair Man

See for yourself...

The ISS has been visible over Blighty every night this week, and will continue to be visible for the next few nights. Check out https://spotthestation.nasa.gov/ for exact times.

On the one hand, it's just a white dot moving across the sky. Boring. On the other hand ITS A SPACESHIP WITH REAL SPACEMEN AND I CAN SEE IT!

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