I've seen papers saying toy ciphers can be improved with powerful key scheduling, but was wondering if there is evidence they are needed in reasonable ciphers? for instance AES. Is there any cryptanalysis which shows a strong cipher becomes dramatically weaker with simpler or no key scheduling?
For example block cipher AES-128, Key size is 128bit and it is used to make a 10 round key which is total 320bit.  Question 1. If i use another Key schedule algorithm in AES, then security decreased or remain same? In other words, if the key schedule algorithm of AES has some relationship with AES encryption itself, then it will be decreased, or it will be same if the new key schedule algorithm is safe enough.  Question 2. Why we expand key? brute force will take O(2^128) time regardless of the key schedule is strong or not. what is the advantage of making key expend? I was curious about this when I was learned about 3DES. Which developed because the former DES has weak key length 56bit so vulnerable to brute force attack, i was wondering why doesn't they just remove key schedule process and use the whole round key as a key.
I want to create this:  Note that wire lay chaotically, so spiral object not the same thing.  There is a cool way to do this task in 3ds max:  Basically he deform straight spline/curve and then bend it couple iterations (over 9000 degrees angle in max).   Blender can't bend that way with simple deform as I know, only up to 360 degree. Is there any other way to make wire wrapping similar to photo? Black holes and positive/negative-energy particles I was reading Brian Greene's "Hidden Reality" and came to the part about Hawking Radiation. Quantum jitters that occur near the event horizon of a black hole, which create both positive-energy particles and negative-energy particles, produce the so-called Hawking radiation. However, I do not understand why only the negative-energy particles are being absorbed into the black hole, while the positive-energy particles shoot outward. Shouldn't there be 50/50 chance that each type of particle is being absorbed by the black hole? Also, the book mentions that a negative-energy particle would appear to an observer inside the black hole as positive. Why? How to kill the process using the name of the program instead of PID? I started my Python program in the background using nohup as mentioned below -   nohup zook.py &amp;   Now I am trying to kill this process so I did the ps command as mentioned below  root@phxdbx1145:/home/david/zook# ps ax | grep zook.py 16352 pts/6    S+     0:00 grep --color=auto zook.py   But somehow, everytime its PID getting changed, I don't know why. Whenever I do like this -   kill -9 16352   It always say, No Such Process.  And when I do px command again, I see that PID got changed automatically..  So I am not sure how do I kill this process?  Is there any way I can kill the process with the name somehow?  UPDATE:-  This is what I am getting. I did pkill -9 zook.py and then I did ps command as mentioned below and it is shwoing zook.py constantly?  root@dbx1145:/home/david/zook# pkill -9 zook.py  root@dbx1145:/home/david/zook# ps ax | grep zook.py 23870 pts/6    S+     0:00 grep --color=auto zook.py  root@dbx1145:/home/david/zook# ps ax | grep zook.py 23872 pts/6    S+     0:00 grep --color=auto zook.py  root@dbx1145:/home/david/zook# ps ax | grep zook.py 23874 pts/6    S+     0:00 grep --color=auto zook.py  root@dbx1145:/home/david/zook# ps ax | grep zook.py 23876 pts/6    S+     0:00 grep --color=auto zook.py Why has a circle when the point light through my glass？ I found there is a circle when the point light through my glass material using the circle render.  How could I solve it? Can I rent a camper in the US/Canada with a European B license? We are considering a holiday in North America with a camper. I have a European driver's license (B) which allows me to drive personal cars up to 3500 kg, although I can imagine that an average camper easily weighs more.  Does my license qualify me to drive a camper? If not, can I take an American/Canadian driver's test which would allow me to drive a camper? How can gravity affect light? I understand that a black hole bends the fabric of space time to a point that no object can escape.   I understand that light travels in a straight line along spacetime unless distorted by gravity. If spacetime is being curved by gravity then light should follow that bend in spacetime.  In Newton's Law of Universal Gravitation, the mass of both objects must be entered, but photon has no mass, why should a massless photon  be affected by gravity in by Newton's equations?  What am I missing? I have a couple of eggs that I've picked up from some Pokestops (I'm lucky enough to live above one).   I walk a lot. I get to work through a 2 mile walk / train journey every day, so I should be picking up loads of steps for the eggs I have. However, because I'm normally always running late... for everything, I have to rush everywhere, so I walk at an above average pace.   Today I've walked around 5 miles, but the game has registered 100 metres. Is this because I walk too fast, or because of something else?  It's worth pointing out that I have the app open when walking... mostly because I have to catch them all. (This made me miss a train this morning... luckily I was early :D) Summation of series $\sum_{n=1}^\infty \frac{n^a}{b^n}$? How can I copy the 5 newest files from a directory to another in a "new to old" order. Android Syntax Highlighting? "like I" or "like me"? In high school we learned to say "than I" and "as I" because you could potentially add an "am" to the end of the sentence.  Examples:  "She is smarter than I."  (Think: "...than I am.") "He is as tall as I."  (Think "...as I am.")  So analogously, shouldn't it be "like I" as well:  "He is sincere, just like I."  (Think: "... like I am.")  But universally, it seems that we use "like me".  Where does this reasoning break down?  Is there history here? Cannot downgrade wpa_supplicant to fix Wi-Fi connection to a corporate network (WPA2/PEAP with no CA certificate) in Ubuntu 18.04 I recently upgraded my Ubuntu from 16.04 to 18.04 (clean install, full wipe). Now I can no longer connect to the corporate network at my office (perhaps related to these bugs: , ). What proved to fix this issue in Ubuntu 16.04 is the answer to ; Downgrade wpa_supplicant to 2.1.  However, even with the linode repository, this fix can no longer be applied. There is no version for wpa_supplicant below 2.6 to the best of my knowledge for Ubuntu 18.04.  My question is this: How can I downgrade wpa_supplicant to 2.1 for Ubuntu 18.04?  Configuration needed for corporate the wifi connection:   Security: WPA &amp; WPA2 Enterprise Authentication: Protected EAP (PEAP) Checkbox No CA certificate required. Inner authentication: MSCHAPv2 What does “{} \;” mean in find (in Linux)? Sometimes I see a command like  find . -name * -exec ls -a {} \;   I was asked to execute this.  What does {} \; mean here? Does "it is entirely possible that" require the subjunctive form of the verb following "that"? Let $f \in L^1(\mathbb{R})$, for $a\in \mathbb{R}$ let $f_a(x)=f(x-a)$, prove that: $$\lim_{a\rightarrow 0}\|f_a -f \|_1=0$$  I know that there exists $g\in C(\mathbb{R})$ s.t $\|f-g\|_1 \leq \epsilon$, this is also true for $f_a$ and $g_a$.  Now I have the next estimation:  \begin{align*} \|f_a-f\|_1 &amp;= \int_{\mathbb{R}} |f(x)-f(x-a)| dx \\ &amp;= \int |f(x)-g(x)+g(x)-g(x-a)+g(x-a)-f(x-a)| \\ &amp;\leq \|f-g\|_1 + \|f_a-g_a\|_1 + \int |g(x)-g(x-a)| \end{align*} my question is: I can argue that $\lim_{a\to0} \int |g(x)-g(x-a)| = \lim_{a\to0} \lim_{T\to\infty} |g(x_0)-g(x_0-a)| 2T$, now I think that I can change the order of the limits here, but I am not sure why?  P.s $x_0$ is some point in $[-T,T]$, and the above is valid from the intermediate integral theorem for continuous functions, right?  Thanks. Is there a difference between "==" and "is"? GPS PPS signal corresponds to data time? I currently have an Adafruit Ultimate GPS connected to an Arduino that outputing GPS data (nmea sentences) once per second.  There is also a pin on the GPS outputting 1 PPS signal.    My question is whether the pulse of the PPS suppose to match the time that the GPS data is coming in i.e are they are coming in at the same time?    Also does PPS pulse come in at the beginning of a UTC second or is it random and simply once a second? What do wizard children do before attending Hogwarts? Most of the wand-carriers that come from a non-Muggle family seem fairly uneducated when it comes to interacting with Muggles.  This implies that they don't go to any type of Muggle school before entering into their education at Hogwarts (or whichever Wizarding school they go to), or else they would at least understand some Muggle culture.  What do children from magical families do before going to Hogwarts if they don't go to a traditional school?  Is there any evidence that they're homeschooled? Checking from shell script if a directory contains files From a shell script, how do I check if a directory contains files?  Something similar to this  if [ -e /some/dir/* ]; then echo "huzzah"; fi;   but which works if the directory contains one or several files (the above one only works with exactly 0 or 1 files). A book suggests that we should not interchange "so" and "so that". "So" means "therefore", and "so that" means "in order that". However, it seems to me that in many cases they don't actually have a difference. For example:     Alice got up at 5:00 A.M., so that she could drive her son to school.   If I substitute "so that" with "so", this sentence presents the exact same causal relation to me:     Alice got up at 5:00 A.M., so she could drive her son to school.   I must have missed something here, since English is my second language. Could somebody explain the difference?