In GPG, we can use same key pair for encryption and signing. Can't/Shouldn't we do this in RSA. I am using  RSAES-OAEP and RSASSA-PSS, not raw RSA btw.
The RSA signature operation is basically the same as encrypting with the private key.  In particular, both operations use the same kind of keys.  Is it safe to use the same RSA keypair both for encryption / decryption and for signing / verification?
PHP regular expressions: No ending delimiter '^' found in What are FML and BWSS? I see this ad sometimes and I would like to know what the acronyms are. Should I sign, watermark or otherwise label a framed print? And if so how? I have an opportunity to show some of my work in a small local coffee shop.  Are there any guidelines/practices to signing, labeling or watermarking a photo which is to be on display?  Or should a photo be signed, labelled or marked at all? Is signing the back of the photo and showing my name on a separate card below the frame itself the "better" way to do this?   I noticed many people on the web put a very noticeable watermark with their logo, copyright and name right on the photo.  Personally, I find this distracting as it often ruins the photograph itself often turning what could be art to kitsch. Painters most often sign the painting itself but this to me is not distracting because it is done with the painter's own hand and it often "works" with the painting. I have a dual boot laptop (Windows 10). I ran general updates and now my Ubuntu won't boot.   I ran in recovery mode and still it freezes in the same place.      Kernel panic – not syncing: Attempted to kill init! exit code=0x00007f00 #include&lt;iostream&gt; using namespace std;  class A  {    int a;    int b;    public:    void eat()    {       cout&lt;&lt;"A::eat()"&lt;&lt;endl;    } };  class B: public A {    public:    void eat()    {        cout&lt;&lt;"B::eat()"&lt;&lt;endl;     }  };  class C: public A {     public:    void eat()     {        cout&lt;&lt;"C::eat()"&lt;&lt;endl;     }  };  class D: public B, C {  };  int foo(A *ptr) {  ptr-&gt;eat();  } main() {  D obj; foo(&amp;(obj.B)); //error. How do i call with D's B part.  }   The above foo call is a compile time error.  I want to call foo with obj's B part without using virtual inheritance. How do i do that.   Also, in case of virtual inheritance, why the offset information need to be stored in the vtable. This can be determined at the compile time itself. In the above case, if we pass foo with D's object, at compile time only we can calculate the offset of D's A part. How soon until I can take my newborn to take a walk outside? I understand that newborn's immune system is still weak and crowds/strangers are to be avoided. Knowing this, how soon can I take my newborn outside, for example to take ~1 hours walk in a non-crowded park? Any particular things to pay attention to when doing this? What Do the Gringotts Goblins Do With Muggle Money? ‘But you’re Muggles!’ said Mr Weasley delightedly. ‘We must have a drink! What’s that you’ve got there? Oh, you’re changing Muggle money. Molly, look!’ He pointed excitedly at the ten-pound notes in Mr Granger’s hand.   Chamber of Secrets - page 47 - UK Hardcover - chapter 4, Flourish and Blotts   So Gringotts exchanges Muggle money for Wizarding money. What do the Goblins do with the Muggle money after the exchange has been made? Is it possible they keep a stash of Muggle money on hand for reverse exchange purposes, or do they surreptitiously feed the money back into the Muggle economy?  What do Goblins do with Muggle money? Why is a home fiber connection asymmetric? I recently switched from an ADSL to a fiber connection and was surprised to see that the bandwidth is asymmetric (1 Gbps down / 250 Mbps up).  While this is understandable in ADSL, I do not understand why fiber at home is asymmetric as well? It is not a limitation of the technology (I have symmetric fiber at the office, and always had) Where, precisely, does feedback on Community ♦ generated flags go to die? For the most part, I treat "Community" like any other user when handling system raised flags. If they are useful, I mark them as such. If they are noise, I dismiss them as such. The Community user has a static flag weight, so our reaction to them is more or less feedback for developers.  Is this feedback from moderators network wide used in any way to help improve the accuracy of system raised flags? Or, would clicking either button suffice?  I'm asking because our reasoning behind declining a flag is now more precise. Does dismissing some as noise help improve the criteria that ultimately generates the flag?  Edit  Yes, thank you Skype, I realize that  asked a similar question . It is stated as a problem in Spivak's Calculus and I can't wrap my head around it. Don't show pending suggested edits to me after I run out of votes How to get the last value of an ArrayList How do I move clock to the right end of GNOME 3 Panel from the middle? How to find the list of all available packages along with the lastest version number available in the repositories? I want to list all the packages(installed or not installed) along with the latest version number available in the repositories.  For example:  The output of apt-cache policy chromium-browser shows like below  $ apt-cache policy chromium-browser chromium-browser:   Installed: (none)   Candidate: 34.0.1847.116-0ubuntu2   Version table:      34.0.1847.116-0ubuntu2 0         500 http://ftp.cuhk.edu.hk/pub/Linux/ubuntu/ trusty/universe amd64 Packages   So the latest version of chromium-browser package available in the repository is 34.0.1847.116-0ubuntu2. Like that, i want to list the version number along with the package names that are available in repositories. And all i want to do this through command-line.  I want the output to be like this,  chromium-browser 34.0.1847.116-0ubuntu2 xxxxxxxxxxxxxx   yyyyyyyyyyy ............     ............ How to fix gaps between flooring planks in mid-1800s house? I live in a mid-1800s house, which I plan to sell this Spring. The original (I think) wood flooring has gaps between the planks, some pretty sizable (photos follow).  Is there any good fix for this? I've seen people use wood filler/epoxy, and it didn't seem to turn out well. Perhaps doing that and painting/dying it black might work better.  I've heard the "old" solution was to pack those spaces with rope, but I don't think that would look better than the status quo.  Any suggestions?  Photos, big gap:    Medium gap:    Small gap: What exactly does ARM sell to vendors? Assumptions:   Computer architecture: Describes how the different modules of a processor interact with each other. A computer architecture is defined using vhdl files Computer Organization: Describes the physical layout of the processor modules on silicon. A computer organization is defined using a set of photo masks (and manufacturing process eg chemical, that goes at each step) Computer Organization, therefore, requires that the fab process be taken into account. ARM is not in the fabrication business, therefore it does not sell photo masks.     My question(s):   What exactly is ARM selling to a vendor (eg: freescale)? For a SoC (System On Chip), (eg: ), which part is ARM and which is Freescale? Who did the integration? Increasing notebook magnification pushes output onto a new line Is logical implication always determinable from just the given statements? I am reading introductory texts on logic and am having a hard time understanding intuitively logical implication.  Specifically, I am wondering if logical implication can always be determined by two statements, P and Q alone? I'll try to give an example to clarify my question.  For example if the statement P is $x = 2$, and the statement Q is $x^2 &lt; 6$, then determining the truth of P $\Rightarrow$ Q is fairly straightforward:   If $x$ does equal 2, then $4&lt;6$ and Q is true, so $P \Rightarrow Q$ is true. And if $x$ does not equal 2, $P \Rightarrow Q$ is vacuously true.  In this example, with two statements P and Q, I can evaluate the truth/falsity of the statement P implies Q. However, what if the statement Q is changed such that it is now the statement $y = 5$?  So now I am trying to prove from that $$x = 2 \Rightarrow y = 5$$  Here is where things get murky for me. Say $x$ is not equal to 2, then $P \Rightarrow Q$ is vacuously true. But what about when $x$ does equal 2, now the statement Q could be true, but it could also be false, depending on some 'context'.   For example, if I said at the start: "Here are two statements, P and Q. Know that x = 2 and y = 4." Given this 'context', $P \Rightarrow Q$ is false. But if I say "Here are two statements, P and Q. Know that x = 2 and y = 5", then now $P \Rightarrow Q$ is true.  My discomfort here is that I assumed with two statements P and Q, I can determine the truth/falsity of $P \Rightarrow Q$ with just this information. Is this the wrong assumption?  As a secondary question, how can the truthfulness of the statement $P \Rightarrow Q$ be variable, depending on context? I have read on some other questions that implication can be interpreted as a promise. So how could it be that depending on some context the promise is sometimes true but sometimes false? Wouldn't this actually mean the promise is not always consistent and is therefore always false?  Some further information in case it is relevant, I recognise that in the first example, the statement Q is 'dependent' in some way on the statement P, since the object under examination in both statements is $x$, whereas in the second example there are two different objects which I am trying to make a logical connection between, which I am thinking may not be valid for some reason. I also recognise that there is still 'context' in the first example, in that we need information on whether $x$ is equal to 2 or not, however in that case it doesn't matter, since $P \Rightarrow Q$ is always true anyway.  Thanks very much in advance. How to create a hole in a polygon in QGIS? I'm trying to use the tool "delete ring" in order to create a hole in a polygon. The geometry of the hole is another feature of the same shapefile   I cannot manage to delete the part of the polygone. Does someone have a tutorial or some explanation? T-SQL stored procedure that accepts multiple Id values Is there a graceful way to handle passing a list of ids as a parameter to a stored procedure?   For instance, I want departments 1, 2, 5, 7, 20 returned by my stored procedure. In the past, I have passed in a comma delimited list of ids, like the below code, but feel really dirty doing it.   SQL Server 2005 is my only applicable limitation I think.  create procedure getDepartments   @DepartmentIds varchar(max) as   declare @Sql varchar(max)        select @Sql = 'select [Name] from Department where DepartmentId in (' + @DepartmentIds + ')'   exec(@Sql)