[No idea if this is the right community so please forgive if not]
More and more I am noticing websites charging for subscription services, whereas years and years ago I suppose when less data was being sent and received [in the days of lower speeds etc.] most websites were free. Youtube is a particular example – now they are offering Youtube Premium whilst introducing inconveniences for free users. Amazon makes less sense to me as surely they profit enough serving as a shopfront, but they have also introduced features such as Amazon Prime.
Apart from the obvious – because who doesn’t want to make a profit – why is this? I would be interested to get some insight from people knowledgeable about this kind of thing as I am only a user and can only guess.
Suppose I’m designing a system where I want to make sure that no single user who goes rogue can commit a malicious action. (I’m ducking the question of how two or more users could collude.) And I assume the machine is physically secure.
One possibility would be to require that the admin logon password be split between two people — one person types in the first 10 characters, the second person types in the second 10 characters. Account protocol dictates that any user who has a portion of the password can be responsible for actions committed from that account — i.e., once the pair log in, both of them have to stay there and babysit each other until they log off from the account. (Because it’s annoying to require two people to be present, the overall architecture should be designed to require the minimum number of actions to be carried out from this privileged account, which is good design anyway.)
One problem is that this is brittle — if one user becomes available, the whole account is inaccessible.
So, instead, the operating system can split the administrator account between 3 usernames, each with their own username and password. The admin login screen presents 2 username/password forms, and to access the admin account, 2 out of 3 of those users have to enter their credentials. This retains the property that no single user going rogue can access the admin account, but it also means that the account can still be accessed if 1 of the 3 users is unavailable.
This seems like a useful feature. Does it have a name? Does any operating system implement anything like this?
(I realize that things get complicated if, for example, you have an encrypted folder on the hard disk, which most systems handle by encrypting the folder in a way that incorporates the user’s password as part of the decryption key. If you want to make sure that the encrypted folder can be decrypted whenever 2 out of 3 users log in, but that no user by themselves can decrypt the folder with their password even if they have access to the data on the hard disk, then you need to encrypt it using a secret-sharing scheme such that 2 out of 3 secrets are enough to decrypt it but 1 is not. This is, however, still doable.)
I have a Windows software that only has 64bit version and I want to run it on my linux computer. I know I can use wine on linux but my OS is 32bit and my hardware supports 64bit I know that I can run a 64bit program on a 32bit operating system using a virtual machine but I don’t know how to do it. I hope someone will show me how to do it.
Until Python 3.4 you were able to determine target’s operating system with Python as follows:
import nmap nm = nmap.PortScanner() scanner = nm.scan(IP, port, arguments='-O') print(scanner['scan'][IP]['osmatch'])
I’m using Python 3.6 and
osmatch returns nothing. Is there a way how to go about this ?
Consider a system with 6 processes, where each process needs 2 copies of Resource R. The maximum units of R required to cause deadlock is ??
The reason why one should disable McAfee before updating operating system to windows 10 is that it might get the software into compatibility issues and can thus corrupt the system functioning and also the antivirus, therefore, it is necessary to get the software disabled while updating the operating system to windows 10. If you still need more help or support then, in that case, connect with the team of trained and certified experts.
Do modern (versions of) operating systems, primarily Android and iOS on mobile, still send targeted or directed probe requests when searching for Wi-Fi networks to connect to?
Such targeted or directed probe requests contain the SSIDs of known networks, and may thus leak information about the sending device’s location history, the owner’s social relationships, etc.
According to this source, modern operating systems do not send these requests anymore:
Around 2014, the privacy implications of targeted probe requests started to become widely publicized and understood. Most new devices therefore stopped sending them. […] When the privacy implications of targeted request probes became widely appreciated, most new mobile devices stopped sending them altogether. […] Targeted probe requests are mostly a thing of the past.
Other sources, like this one or this one, seem to confirm that targeted probe requests are not sent anymore on the latest versions of Android, at least.
If this is indeed true, and perhaps also for iOS (and some desktop OSs), are there any press releases, bug tracker entries, security reports or code commits that confirm this?
Directed probe requests, as opposed to broadcast requests that don’t contain a network’s SSID, should only be necessary for hidden networks. The impact is stronger on mobile devices, where you tend to both have more known networks added to your device and broadcast that list in more places.
Some facts about “Segmented Paging”
1) Each process has one segment table.
2) There is one-page table per segment.
Fact about “Paged segmentation”
3) Contains page table of segment table.
Now consider following problem
In a paged segmented scheme of memory management, the segment table itself must have a page table because. (A) The segment table is often too large to fit in one page.
(B) Each segment is spread over a number of pages.
(C) Segment tables point to page tables and not to the physical locations of the segment.
(D) The processor’s description base register points to a page table
Given solution is:
Here option (A) is true , as segment table are sometimes too large to keep in one pages. So, segment table divided into pages. Thus page table for each Segment Table pages are created.
I believe a page can contain several hundreds of segment table entries of form
<segment base, limit>
I only came across code, data, stack and heap segments. I believe a process can have only these “four” segments. And also, we know each process has a segment table (Fact 1). Then how a segment table can grow so large that it cannot be fitted in a single page?
I didnt install ubuntu but it opened,now I want to go back to the previous operating system,but I cant find a way for it.
I have acquired several zonar tablets and would like to be able to reprogram them and wipe any original software with out loosing the functionality of the components like camera speakers screen etc Where would I start and how would I go about creating software for it