Wikipedia:Reference desk/Archives/Computing/2018 December 13

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December 13

Data wiping: what if attacker knows the PRNG seed?

Does data recovery after apparent data erasure actually become easier if the attacker can reconstruct the stream of pseudorandom bytes used to overwrite the data (e.g. the attacker knows what wiping program and what PRNG seeds were used)? NeonMerlin 03:13, 13 December 2018 (UTC)

If you overwrite the data with pseudorandom data, I don't think so (unless you get into the disk physically like I've heard can be done). Now if you did something like XOR the existing data with pseudorandom data, and someone knew the details of the random number generator, then yes. (but why would you do that?) Bubba73 ^{You talkin' to me?} 04:13, 13 December 2018 (UTC)

If you mean for something like a hard drive, by all indications just overwriting with zeros is enough to wipe everything, unless data can be recovered from remapped failing sectors or stuff like that. In ancient times (1990s) it might have been possible to read through a layer of overwrite,[1] so various silly multiple-overwrite schemes were deployed, but these days drive data is too dense and too intricately encoded for that to have any hope. See notes at secure erasure. But, a secure PRNG should generally try to implement forward secrecy. Fortuna (PRNG) is a well kmown method for that. 173.228.123.166 (talk) 05:23, 13 December 2018 (UTC)

Troubles with Windows 10 multi-desktops

It happens that by some erroneous key combination (I never quite figured which, I think it involves the WinKey) Windows 10 separates each application to its own desktop. I can switch desktops with WinKey+Tab, but I can no longer use drag-and-drop between windows. Also, switching apps become a keyboard action instead using mouse on the taskbar. Annoying.

I tried to find a solution to merge back all the desktops to a single one. I found three suggestions that simply do not work: After WinKey+Tab dragging on desktop to another (doesn't do anything), right-click a desktop, hover over "move to" and send it to another desktop (again, doesn't work: the only option that pops out is "new desktop") and closing a desktop using the top-right X that simply close the desktop with the app.

The multi-desktops icon on the taskbar is missing.

Any solution? It seems the multi-desktop on my system is buggy. How can I disable it, or combine back all the desktops to a single one?

אילן שמעוני (talk) 11:23, 13 December 2018 (UTC)

Microsoft has switched out the multi-desktops icon with the "Task View" button; next to Cortana. To move apps into another desktop, press the Task View button (or WinKey+Tab), and hover your cursor over your desktop. When it switches to view your apps on that desktop, you should be able to click and drag to move the app over to the other desktop. Hope this helps. Slapblackjack (talk) 01:00, 14 December 2018 (UTC)

As I stated, this method is broken in my Win 10 - it simply doesn't work (as well as the other documented methods), so I'm looking for a way to disable multi-desktops altogether. אילן שמעוני (talk) 13:37, 14 December 2018 (UTC)