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Back in 1993, I was taking a number theory class

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Re: Back in 1993, I was taking a number theory class

#121

Post by throwaway3699 »

knodi123 wrote: post #48
jmercouris wrote: post #11

I remember in high school renaming programs to "calc.exe" so we could run them. Back when these kinds of protections were so primitive :-)

Ah, the era of primitive DIY security. Those were the days. It's kinda of sad that today's kids have to deal with industry-grade encryption and professional best practices, instead of going toe-to-toe with an underpaid self-taught middle-aged "computer guy" like my generation did...

I had a few amusing tactics. Even with 'professional best practices' (debatable), the human element was still vulnerable.

One example was that my school refused to give out the Wi-Fi password as a form of security, so they'd demand to manually type it in themselves on your machine. A simple keylogger and now the whole school just ignored that rule for a few months.

Another is that while they tried to block things like SSH, VPNs, etc... to get around the school's internet filtering, turns out you could just run SSH over port 80 and have a tunnel out :)

Re: Back in 1993, I was taking a number theory class

#122

Post by megameter »

throw5away wrote: post #43
SilasX wrote: post #12

> On these computers, I could factor a general number with around 70 decimal digits in a reasonable amount of time (like overnight). What’s the comparable figure you could get on typical hardware in today’s university computing clusters or computer labs?

I generated two random 35 digit primes, multiplied them, and then tossed the product into the first hit for "factor integer online": https://www.alpertron.com.ar/ECM.HTM 1731 322587 637083 705865 442033 654804 904216 446486 784497 444181 466938 498269 (70 digits) = 25317 847509 490819 861309 522806 413689 (35 digits) × 68383 482718 586893 688113 139227 257221 (35 digits) Time elapsed: 0d 0h 0m 23.8s This is in JavaSc…

Ran the same program and input on my phone.

Time elapsed: 0d 0h 5m 38.2s

Re: Back in 1993, I was taking a number theory class

#123

Post by jcims »

elengyel wrote: post #19

I'd like to clarify that my code was running only on machines that were otherwise idle. Not many people were in the lab late in the evenings. MPQS processing nodes could be added and removed dynamically, so if somebody needed a computer that was part of my cluster, they could just quit my program and everything would go back to normal. Also, once the number theory professor learned of what I had implemented, he worke…

Right about that exact same time I commandeered an entire lab (30-40?) of SGI Indigo 2's at Ohio State to do distributed raytracing. Wasn't nearly as educational or diplomatic but I did have fun with it until I got shut down for essentially using twice the storage in my home directory as the entire rest of the class. Between that, usenet (of course) and trolling cuseeme reflectors all over the world from the odd smelling Mac lab, I didn't get much studying done.

Good times.

Re: Back in 1993, I was taking a number theory class

#125

Post by Agnolo_Giotto »

elengyel wrote: post #19

I'd like to clarify that my code was running only on machines that were otherwise idle. Not many people were in the lab late in the evenings. MPQS processing nodes could be added and removed dynamically, so if somebody needed a computer that was part of my cluster, they could just quit my program and everything would go back to normal. Also, once the number theory professor learned of what I had implemented, he worke…

Would be cool if you tried running this on the Golem network now. https://www.golem.network/

Re: Back in 1993, I was taking a number theory class

#127

Post by exikyut »

dsr_ wrote: post #51
linux2647 wrote: post #7

Thread on a single page: https://threadreaderapp.com/thread/1389106103179378689.html

Everything interesting on twitter takes more than one tweet. I wonder if there's a place for "fast Usenet", where you can write a message of arbitrary length with some markdownish syntax, let it be flooded to anybody subscribed to that group, and automatically drop into a searchable no-new-comments archive after, say, a week.

Curious why your comment got collapsed, it's very interesting.

Genuine question: why archive?

While I don't really have a substantive list, I very often come across archived threads on here and elsewhere that I'd like to respond to. "Wow this is awes--" "oh it's from 2016".

I guess I just don't understand the hate against necroposting. If there's a thread out there that has exactly the context and disposition I was looking for, _let me respond to it_. In a lot of cases I don't actually care if any reply(s) take 4 years to come through!

Re: Back in 1993, I was taking a number theory class

#128

Post by exikyut »

2sk21 wrote: post #38

I have a similar story but I was not quite so clever. Back in 1990 and 1991, I used a cluster of IBM RS6000 workstations in my university to train neural networks. I had previously tried to get backpropagation to work on a Connection Machine but found it too frustrating to work with. The cluster of RS6000s actually ran my code (written in C) very fast and was able top get some good results and graduate with PhD. I bu…

Do you remember why the CM was so frustrating? That's a very ironic story right there.

Re: Back in 1993, I was taking a number theory class

#129

Post by shakna »

mxcrossb wrote: post #87
tanbog4 wrote: post #61

When I did a university security course a few years ago that involved a contest to factor primes those of us who wanted to be competitive had to buy AWS processing time...

Time to take a hint from the college board and insist that every student’s code has to run on a TI-84

At which point you should break out KnightOS [0]

[0] https://knightos.org/

Re: Back in 1993, I was taking a number theory class

#130

Post by kqr »

a3n wrote: post #45

In 19 and 82 or 3, I worked at Lockheed Shipyard in Seattle, in a sort of tech writing capacity on a Navy ship building project, based on my recent experience in the Navy. The business closed with completion of the ships. We had to fill out lots of forms that documented what we called "analysis," and we'd often have to change them based on some factor changing. One change could cascade through the whole form. Paper f…

It sounds like you essentially invented the spreadsheet. Nice work!

> Part of the calculation involved sorting. I didn't know anything about sorting, so I implemented what I later learned was bubble sort. Because that's obviously how you'd do that.

I would like to politely contest the authenticity of this specific detail. In my fairly strong collection of evidence, people just do not bubble sort without being told how to do that.

People's natural mental sorting algorithm is most often insertion sort. That's what you use when you hold a hand of playing cards, for example. Sometimes something else (radix sort with monopoly money, for example), but I've never seen anyone invent bubble sort without first being told about it one way or another.

(Which is a good thing because bubble sort is just such a stupid idea I don't know why we teach it. In my life, I've only ever been notified of one single good use case for it: you need to slowly converge on an order but the minimum amount of computation is necessary for each step of the convergence.)

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