Yeah, it's between 1200 baud and 2400 baud - which would be right around where dialup was in the 80s. Plus the attack runs at 3.9KB/s on AMD processors - over 10 times faster!
Fair! Thanks for the correction. I intended to say bits per second. Luckily I think I’m still in the right ballpark for speeds (at least in the early 80s).
Did any of those old modems use QAM? It seems like many of the older protocols were FSK/PSK-based (yes, special cases of QAM, but not decoded the same way).
Good question. I've long since tossed my various modems from the epoch. I started using dial-up systems around 1987 or 1988, working through 300, 1200/75, and 2400bps, etc.
Referring to wikipedia [0] I note v22.bis was released in 1984, and while they're a bit vague, they suggest 2 or 3 bits per signalling change in those 1200bps modems.
I also recall, though perhaps later, vendors were often champing at the bit with 'proposed spec' compliant hardware available prior to the formal specifications dropping, so it was not uncommon to have some of those new speed devices prior earlier (obviously with some risk attached). I think that was more around the 14400bps era though.
Anyway, my extremely solid Telecom 2400bps modem was almost definitely running at 600baud (produced in the late 1980's, though in my possession from very early 1990's).
Depressingly, a lot of ostensibly tech articles (eg [1]) conflate baud with bps, making them poor-use / low-trust historical references.
It’s a fair point but also back in the day - “everybody” (especially the younger BBS and hobbyist crowd) incorrectly referred to them as 1200 baud or 2400 or even 9600 baud modem - as evidenced by the numerous historical references.