What does the "bonus" tag over the score in NBA games means?
What does the 'B' (or bonus) mean on a basketball scoreboard?
Is there a way to make RC4 (ARCFOUR) secure, or is it completely broken? I need a method to authenticate a process with another in order to establish interprocess communication between them, to prevent malicious processes from trying to hook onto the system. Currently I just send a password in plaintext between the two processes and the host process just performs a string comparison with its copy of the password, and will disconnect the connecting process if they don't match. It was fine when I was limited to connecting each process on localhost, but obviously this is not secure if someone just happens to have access to a network between each process and could sniff the packets. Do note that I only care about encryption for the password exchange and I don't really need it to secure the communication.  So basically I need a encryption algorithm that doesn't need to protect its contents well but does need to protect its key, and needs to be as fast as possible with minimal RAM usage and I/O overhead. Yes, data exchange is more CPU-bound than I/O bound since the two processes will be doing loads of calculations and they most likely will be connecting through localhost. Now, I came across RC4, which has a throughput of over twice that of AES-128, but it is evident that it has some weaknesses and I have a lot of questions about how to implement it in a secure way.  Well first question - it's in the title. Is RC4 completely broken and should be avoided? I hear a lot of "it is secure if properly used" and then a lot of "use of RC4 is discouraged."  I was planning to keep the plaintext password on both processes and have them SHA-224 hashed, and concatenate the hash with a 32-bit IV as a 256-bit key for RC4. Are there any security risks with this approach? Perhaps I could then hash the concatenated IV and hashed password with SHA-256? I'm well aware that WEP was cracked because it used a 24-bit IV, but a 32-bit IV has over four billion more unique values. Should I avoid incrementing the IV after each packet like WEP?  And when it comes to RC4-drop[n], what is a reasonable value for n? 256, 512, 768 bytes? How would you implement drop n on a library whose only public operation is encrypting a byte array - pass a byte array of length n after the engine is initialized with the key? Would that mean you would have to basically process n empty bytes after every time you change the IV (which happens after every packet)?  Sources:   EDIT: after reading all these excellent responses, I realized how ignorant I sounded about the whole subject. I had no experience with cryptography before this day, and I only was able to read about RC4's risks from the limited Google results that I could barely follow. thank you to everyone who has been patient with me!  Correct me if I'm wrong, but I believe a better solution is to either use AES (which is not slower because re-keying RC4 after each packet is expensive) or an universal message authentication code. I can easily work with AES, but my understanding of MAC is a bit shaky. An IV is only secure if the update sequence is randomized and unpredictable, meaning I would have to send a 128 bit IV for every message that is sent, which can add a 400% overhead to the short, 4 byte packets that are commonly sent by my application. HMAC can add more than twice that amount if SHA-256 is used. I am going to have to investigate this matter further. I need backup in pressing my case that the phrase “choose from one of four options” is grammatically incorrect. Is there some resource that can prove my case, that the incorrect phrase should be replaced with one of the two following ones?        Choose one of four options   Choose from four options Can't plot with gnuplot on my Mac Solvability of Poisson's equation for $p$-forms directly from Hodge decomposition If $M$ is a closed manifold, it's well known that $\Delta\phi=\alpha$, where $\alpha$ is a $p$-form, has a solution if and only if $\alpha$ is orthogonal to the space of harmonic $p$-forms. This is proved on page 224 of Warner, but the proof depends heavily on his approach to Hodge theory. There are other methods that avoid his main technical lemma 6.6. So, can one prove this fact using only the "standard" facts of the theory?  For functions it is easy, for one has $$\alpha=\delta \psi+h.$$ But $(\alpha,h)=0$, so $\alpha=\delta\psi$. Then decompose $\psi$ to get $\alpha=\delta d\zeta$ for some function $\zeta$. But on functions, $\Delta=\delta d$. But for $p$-forms in general one has $$\alpha=d\xi+\delta \psi+h,$$ since $\Omega^{p-1}$ is nontrivial. Using the decompositions again, one has $$\alpha=d\delta \rho+\delta d\sigma,$$ where $\rho,\sigma$ are $p$-forms. I don't see how $\rho$ and $\sigma$ are related, but it looks close. I have from Exercise 1 pg 33 - "Algebra - T. W. Hungerford" following:      Question to proof: Show by example that the first conclusione may be false if $G,\, H$ are monoids that are not group.   I thinked:     Proof: let be for example two monoids $(G:=\{\emptyset\}, \bot)$ and $(H:=\{\emptyset, \{\emptyset\}\}, \top)$ with: $$\begin{array}{c|c} \bot &amp; \emptyset \\ \hline \emptyset &amp; \emptyset \end{array} \, \, \, \,\, \,\, \,\, \,\, \,\, \,\, \,\, \,\, \, \begin{array}{c|cc} \top &amp; \emptyset &amp; \{\emptyset\}\\ \hline \emptyset &amp; \emptyset &amp; \emptyset \\ \{\emptyset\} &amp; \emptyset &amp; \{\emptyset\} \end{array}$$ $G$ with $e_G:=\emptyset$ like neutral element and $H$ with $e_H:=\{\emptyset\}$ like neutral element. Let be $f$ a function from $G$ to $H$ with $\emptyset \mapsto \emptyset$ (namely $x \mapsto x$), the function is Homomorphismus in fact $$ \begin{align} {\color{Red}f}{\color{Red}(}{\color{Red}x}{ \color{Red}\bot }{\color{Red}y}{\color{Red})}=&amp;f( \emptyset \bot \emptyset)= {\color{Green}f}{\color{Green}(}{\color{Green}\emptyset}{\color{Green})}= \emptyset \\ {\color{Red}f}{\color{Red}(}{\color{Red}x}{\color{Red})} {\color{Red}\top} {\color{Red}f}{\color{Red}(}{\color{Red}y}{\color{Red})}=&amp;f(\emptyset) \top f(\emptyset)= \emptyset \top \emptyset= \emptyset \\ &amp;\text{with }x,y \in G \end{align}$$ but it means that $$ \begin{align} f(e_G)&amp;\neq e_H \\f(e_G)={\color{Green}f}{\color{Green}(}{\color{Green}\emptyset}{\color{Green})}=\emptyset &amp;\neq \{\emptyset\}= e_H \end{align}$$ Therefore $f$ ist Semigroup-Hom but not Monoid-Hom...   Is it correct? Can we have a moderator only "flag for community team/developer attention" link on posts? There are times when moderators come across things that only Stack Exchange employees can deal with. These include things like deleting sensitive information permanently from posts disassociating users from posts that require direct database access.  (The previous use case is now possible for moderators to do directly the moderator redaction tool)  Currently the workflow is:   See the post (either in normal site usage or via a flag) Go to chat Ping one of the community team (if they are around) Explain the problem   A far better workflow for the moderator would be to simply able to flag the post so it then appeared in an "employee only" queue somewhere. This could either be a page on the main Stack Exchange site or (better still) their inbox.  (OK I admit I hadn't fully thought this last bit out.)  This could either be a moderator "flag to devs" link on the post or a new option on the existing flag dialog (probably the better solution).  Now that moderators can't merge we have a fairly common situation where this would be very useful. A new users posts an answer (or question on sites that don't require registration) then loses their cookies and ends up creating another unregistered account (or two). Eventually the might even create a registered account. It used to be easy to merge the unregistered accounts into the registered ones, but now we either have to badger the OP to use the "merge accounts" form or ping the team somehow.  Having the "flag for team" option would be very useful in this scenario. [See  for more on this topic, as well as better illustrations of the final product.]  I have a document with a lot of short excerpts from another book scattered through it.  Putting frames around them looks a little too 'clean'. How can I get a 'torn page' type effect, to make it look as if the excerpt has been physically torn out of a book?  (I've occasionally seen this done in printed books, although I can't find an example right now.)  I'm not wedded to a very specific look here --  gives plenty of examples. But just to give this some frame of reference, here are some of the nicer ones:          (The strong colouration in this second example is a probably a little too distracting for actual use, although it might be interesting as an option. It's more the edge effect I'm interested in.)    Edit (again): I tried typesetting my text according to the updated versions of the answers below. Here are the results:    Or with interpolated shading: Is there a such thing as an exchange program in Harry Potter? In the Harry Potter universe, is there any mention of an exchange student at Hogwarts or one of the Hogwarts students going on exchange at another school?  This happens all the time in the "muggle" school systems I'm sure it would happen in the wizarding schools as well. How to turn the white colour portion to transparent I got this map icon in work in illustrator, and would like to turn those white dash line and the white outline of the location mark to transparent. Can you please advise me how to do it? Thank you in advance. sudo apt update always giving Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?) In the following sentence, I want to know if I've understand the correct meaning or not:     This version holds that the wave function does not so much describe the state of the physical system as the state of our knowledge of the system.    Can we say that it means the wave function describes the state of our knowledge  of the system more than it describes the state of the physical system  ?  It is worth noting that in the Cambridge Dictionary, we read:  not so much sth as sth ​ If you say that something is not so much one thing as something else, you mean it is more the second thing: They're not so much lovers as friends. I don't feel angry so much as sad. Do these new insights into prime numbers affect encryption security? reports:  Two mathematicians have uncovered a simple, previously unnoticed property of prime numbers [...]. Prime numbers, it seems, have decided preferences about the final digits of the primes that immediately follow them. Among the first billion prime numbers, for instance, a prime ending in 9 is almost 65 percent more likely to be followed by a prime ending in 1 than another prime ending in 9.  Do these insights make breaking keys based on primes more mathematically plausible in a shorter amount of time? Is there a description of Stack Exchange/Stack Overflow sites? How do I convert the coordinates of a click to a tilemap position? How do you turn a tilemap (produced by TileD) for cocos2d where I can click on individual items and get a callback?  Is it just a case of converting captured touch and finding out where it is on the tilemap and then converting that to pixels  -- but that doesn't say what item was clicked on.  I have a tilemap of a city with buildings on it, and I'd like to be able to click or press on a specific building, get a callback.  What would be the best way to accomplish this? I'm having trouble with this functional equation, to find all functions $f:\mathbb R \to \mathbb R$ for which the following is valid for all $x,y\in \mathbb R$: $f(x) + f(x+f(y)) = y + f(f(x) + f(f(y)))$ I haven't been able to pinpoint any solution, nor to prove surjectivity or injectivity. So 0 progress. Tried with $x=y=0, x=0, y=0, x=-f(y), y=f(x)$, and even with some assumptions on bijectivity, but nothing helped. I don't know the source but seems like a pretty difficult problem, maybe even impossible to solve. A real solution to ambiguous tags Introduction Even within a site's relatively focused range of topics (it's unlikely anybody on SO will think  refers to the solar system's star), some tags are inherently ambiguous. There are currently two unsatisfying options:  Declare that the tag is only to be used for one of the possible meanings, write a tag wiki explaining it, and link from there to the newly created tags for the other meanings, and keep cleaning up the tag whenever someone ignores the tag wiki popup explaining the tag. Use alternative tags for all meanings (e.g. cd-command and compact-disk, instead of cd), and keep removing the undesired tag whenever it pops up again. And it will. The  is not deterring users from creating unnecessary or redundant tags.  Blacklisting tags is a complicated ritual occurring once in a blue moon, at most, and involves a dragon, a team member, and sacrifices to be burnt. It also makes those other, unambiguous tags not easier to discover, if it were applied to ambiguous tags. I don't consider this to be a viable option in this case. Proposal Here's the proposed : Just like a tag can be declared a synonym of another tag, basically changing all references to the synonym to references to that other, canonical tag, it should be possible to make it a disambiguation tag (or ambiguous tag) for multiple other tags. It's a logical progression from &quot;You entered a term with the same meaning as this other term&quot; to &quot;You entered a term with the same meaning as one of these other terms, please choose the correct meaning&quot;. Use of the tag should force the user to choose one of the alternatives presented:  &quot;, did you mean  or ?&quot; &quot;, did you mean , , or ?&quot; &quot;You entered 'vm', did you mean  or ?&quot; &quot;You entered 'sas', did you mean  or ?&quot; &quot;You entered 'kvm', did you mean  or ?&quot; &quot;You entered 'mono', did you mean  or ?&quot; &quot;You entered 'dsl', did you mean  or ?&quot;  Not all of these examples might be good (I'm not sure e.g. about the first two SO examples), but that's not really the point here anyway — they should just convey how this could be used. Note how some of these tags would probably never be used if users had to type them, and yet everything shorter is ambiguous. This could probably be mostly solved by extending the synonym/tag wiki excerpt dropdowns shown when a user enters the tags, proposing the alternatives for an ambiguous tag entered by the user (like a synonym suggestion, but with multiple options). If ignored, the user could still be shown an error message like with blacklisted tags, but by designing the selection dialog well, it should be possible to prevent that in most cases.  Related topics   This topic is related, but the user seems to have accepted the inclusion of tag wiki excerpts in the tag suggestions drop-down as sufficient.   This requires extensive discussion and team involvement (i.e. the status quo)   This topic has no real solution, except manual retagging. Why does the road look like it's wet on hot days? Often, I'll be driving down the road on a summer day, and as I look ahead toward the horizon, I notice that the road looks like there's a puddle of water on it, or that it was somehow wet. Of course, as I get closer, the effect disappears.  I know that it is some kind of atmospheric effect. What is it called, and how does it work? Disable two column mode for separate part I am writing a document using the report class in two column mode, but I need a \section to spread across both columns, but how can I set that?  Something like  \documentclass[10pt,danish,a4paper,twoside,twocolumn]{report} \input{preamble.tex} \begin{document}  % This section should spread over both columns \section{Name}  \lipsum[1-3] \end{document} Why are the longer edges being beveled more? Network booting couldn't find kernel image I have a problem with PXE booting. I followed  on the Ubuntu help wiki. But I get an error on client machine:  Could not find kernel image: vmlinuz-3.13.0-24-generic   And now, question. This image should be in pxelinux.cfg folder, am I right?