For example, take K1, from the Kryptos sculpture, which has been long solved. It's text is as follows:  EMUFPHZLRFAXYUSDJKZLDKRNSHGNFIVJ YQTQUXQBQVYUVLLTREVJYQTMKYRDMFD  Now, I already know they keywords used (because the solutions are online) and they are PALIMPSEST and KRYPTOS. However, I do not understand how you would go about finding these keywords if you do not already know them.   Any help would be appreciated!
What would be a good way to go about attacking a Quagmire 3 cipher?  I understand that it is polyalphabetic with a key and an indicator. I have started by taking the cipher text, taking every n-th letter and putting that in a string, computing the index of coincidence for the n strings I get and then averaging that. I would assume that whatever n value corresponds with the closest average index of coincident to English (0.066) would be the number of alphabets, i.e. the length of the indicator.  Where do I go from there? Or is my approach incorrect?
I know that the Linux kernel supports TRIM as of version 2.6.33, so there should be TRIM support in ubuntu.  Is TRIM enabled by default or do I need to change some settings or install additional software for it to work? If so, how? How could Luke hide from Vader during the duel on Death Star II? In Return of the Jedi, Vader throws his lightsaber at Luke causing the catwalk come crashing down. Luke uses this in his advantage and hides from him under the throne room platform. Unable to locate his son, Vader tried to lure Luke out of hiding.  But how could Luke conceal himself from Vader in the first place? Did he use a Force power of some kind to blur Vader's sensors? I mean, the underneath of the platform was pretty much an open space with very little possibilities for hiding. The only places I see in the movie are the openings on the both sides of the floor (pointed by the yellow arrows):    The background of a close-up to Luke doesn't give much of a clue (although there is a round shape which could be the bottom of a window frame):    But as Luke reveals himself, he appears to be beneath of the staircase to the dais, right in the middle of it:    There's no way he could have hidden there all the time, because just a couple of seconds before, Vader walked towards and stared at the very same spot:    My first ideas were that Luke used the Force to make himself invisible, or to teleport him to the position. But after taking a look at one of the cross sections of the Emperor's throne room, I assume Luke could have slid almost straight under the floor of the lower level (yellow arrow) and then later  back to the staircase (although we don't see it in the movie, and I'm not sure if Luke knew the ability):    Does someone know better? Is the expression "yesterday afternoon" correct? Is it proper to use the following expressions  I started to London yesterday afternoon . I started to London yesterday morning  I ask because it is supposedly correct to say 'last night'. Why don't we say 'last afternoon' or 'last morning'? How do I force Excel (and other Microsoft Office products) to stop opening files in the same application? Whenever I "double click" on an Excel file and another Excel file is open, the newly opened file automatically opens in the same application window as the previously opened Excel file. This isn't limited to just Excel, as I've seen Word do this as well. This poses a problem when wanting to compare documents side by side.    The current solution I have for this is to actually open another Excel or Word instance, and then open the file from within that application window itself. Is there a way to force Office to open a new instance of the application when double clicking on the file icons?  I'm currently using Office 2007 and Windows XP, but I've seen this on Office 2010 and Windows Vista and 7. I'm looking for an overall solution if possible. How can I get a DisplayLink USB monitor work under Ubuntu? I have a DisplayLink-based external USB monitor, which has both power and data over USB, and seems to work perfectly under Windows 7, but only can display a text console under Ubuntu 10.10, and that I can only use when I am actually switched to it. So the only Use I can have so far is to have some text-based monitoring or console that I can watch while working on the graphic display.   I know there are some development done for DisplayLink, but I never could get it to actually run properly.   Yes, I tried the detailed setup described in other , but they did not work, and instead crashed my X that I had to restore.   Merci :-) Imagine a situation in which the whole place is on fire, a bomb is about to explode, everyone is running for their lives and someone is checking his looks on the mirror... pretty inappropriate for the situation, don't you think? I'm looking for an idiom or colloquial/slang/informal expression to describe such an indifferent stance. *.xhtml url-pattern causes java.lang.NullPointerException at com.sun.faces.context.flash.ELFlash.loggingGetPhaseMapForReading How does ServerName and ServerAlias work? I stupidly ran sudo rm /* followed by sudo rm -R /*  My sites still run, although the vast majority of commands like ls are now broken.  Is there a simple way to get data off the server or reverse some of damage? Java method dispatch with null argument Why does it (apparently) make a difference whether I pass null as an argument directly, or pass an Object that I assigned the value null?  Object testVal = null; test.foo(testVal);    // dispatched to foo(Object) // test.foo(null);    // compilation problem -&gt; "The method foo(String) is ambiguous"     public void foo(String arg) { // More-specific     System.out.println("foo(String)"); }  public void foo(Object arg) { // Generic     System.out.println("foo(Object)"); }   In other words, why is the (commented-out) second call to foo(...) not dispatched to foo(Object)?  Update: I use Java 1.6. I could compile Hemal's code without problems, but mine still doesn't compile. The only difference I see is that Hemal's methods are static while mine are not. But I really don't see why this should make a difference...?  Update 2: Solved. I had another method foo(Runnable) in my class, so the dispatcher couldn't unambiguously select the single most specific method. (See my comment in Hemal's second answer.) Thanks everyone for your help. Let $x,y,z&gt;0$: Prove that:   $\frac{1}{(x+2y)^2}+\frac{1}{(y+2z)^2}+\frac{1}{(z+2x)^2} \geq\frac{1}{xy+yz+zx}$  I tried to apply Cauchy - Schwarz's inequality but I couldn't prove this inequality! If in a topological space only finite subsets are compact sets, is it then the discrete topological space?   Thank you. Find a non-negative function on [0,1] such that $t\cdot m(\{x:f(x) \geq t\}) \to 0$ that is not Lebesgue Integrable 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. Only ftps with proftpd on debian What does this notation mean? F|U If $F$ is a function and $U$ is a set, then what does $F|U$ mean?   In , the Inverse Function Theorem, the notation is used  Also, the file in stating the Lemma 2.14 states that $A \in U$, what does this mean? A set is an element of another set? What is $A$?  EDIT: Could someone kindly explain to me what is going on in Lemma 2.16. How does $\delta$ come into play? I dont see the role in the lemma. I also don't see why this proves one-to-one R linear regression categorical variable "hidden" value K-means - comparing solutions with SSwithin elbow-method: minimum "too early", or non-monotonic curve Which form should be used for at­tribu­tive nouns like “stu­dent union”: sin­gu­lar or plu­ral, or pos­ses­sive sin­gu­lar or pos­ses­sive plu­ral? When should a noun that’s used at­tribu­tively to de­scribe an­other  noun be plu­ral, and when should it be sin­gu­lar?  And when should it be pos­ses­sive, like bak­er’s dozen and when should it be plu­ral pos­ses­sive, like farm­ers’ mar­ket?  In other words, why do we say teach­ers union rather than teacher  union?  And why do we say wed­ding plan­ner rather than wed­dings plan­ner?  Which of these vari­ants is or are cor­rect?        stu­dent union   stu­dents union   stu­den­t’s union   stu­dents’ union      What about com­mu­nity val­ues ver­sus com­mu­ni­ty’s val­ues?  Please note I am look­ing for a gen­eral rule or at least some tips.  These are only ex­am­ples.  Up­date: It seems even na­tive speak­ers fol­low their per­sonal  style to write such com­pound words. I won­der why in the IELTS lis­ten­ing sec­tion, the lan­guage learner has to write a spe­ci­fic form and there is no rule for this. How to make sure that Thinkpad discharges external slice battery first? The thing is that when an external slice battery pack is connected, the laptop first discharges the internal one. This is a problem because then it is impossible to switch between multiple external battery packs without powering off the laptop. It is also not possible to just disconnect the external battery pack when you e.g. need to insert it into a docking station.  Thus, my question: how to change the discharge order under Linux?  For my use cases following order would make much more sense: when an external slice battery is connected, first discharge it completely before using power from the internal battery.  Background: For some Thinkpad models (e.g. X220) there are slice battery packs () available that you can connect to the bottom of the laptop (similar to a docking station).  They seem to be supported well on Linux - e.g. the Gnome Shell battery applet includes both batteries (internal and external) when connected - including displaying the current capacity for each.