I've never really understood the fundamental basis for this objection. It's inconvenient, it drains power on laptops, sure, but to me, those are annoyances and not fundamental flaws.
It's a minor annoyance for desktops. A minor one, but one that I shouldn't have to deal with. A constant reminder of DRM.
But it's more annoying for laptops. When I'm traveling, I don't want to take a cake box of CDs with me, but I often do want to play video games on the plane. What's more, my current laptop (a Thinkpad) doesn't even have a CD drive, so I'd have to bring a big honking external drive, and even that wouldn't work on a plane, because I'd need to power it.
The idea is to set IO = ST RealWorld. Since you can only purify things of type (forall a . ST a), you still can't purify IO. On the other hand, you then don't have separate types for IORefs and STRefs, IOArrays and STArrays, and so on.
It'd be extra neat if they could do it with STM as well, but that seems unlikely. IORefs and STRefs are the same on the inside, but TVars are not, so it'd take some deep compiler hackery.
Haskell has a very nice software transactional memory library, which makes a lot of otherwise-difficult concurrency problems much easier. It's statically safe, too, unlike similar libraries for imperative/OO languages.
Certain other language features are very nice. Monads are also extremely powerful once you wrap your head around them, and the type-class system and standard libraries make a lot of math programming problems much easier.
The language also has downsides. The laziness makes it possible to build up an arbitrarily long chain of suspended computations, which amounts to a hidden memory leak. Laziness also complicates the semantics for "unchecked" exceptions, most notably division by zero. The combination of laziness and purity can make the language very difficult to debug and optimize. While the compiler has very powerful optimization capabilities, sometimes code needs to be just so to use them (like flagging things "const" or "restrict" in C), and this can make it hard to write clean code that runs fast.
The other problem is that most programs need some amount of imperative code somewhere to do the I/O. This code has a tendency to be verbose, nasty and slow in Haskell.
There are also some problems that would be relatively easy to solve in a very nice way within the semantics of the language (give or take), but are not solved well in the standard libraries. These include exception handling, global mutable state, strings and regular expressions, certain I/O operations, arrays and references. It would be very nice if the ST and IO monads were unified, and if references and arrays had nice syntax; this would reduce the ugliness needed to write those occasional bits of imperative code.
What this all means is that Javascript is the most widely deployed functional language in existence!
Javascript is probably the most widely-deployed programming language in existence. Nearly every PC, nettop and smartphone has at least one complete Javascript implementation on it, and many of them have more than one. The same is not true for any other programming language I can think of, unless you count i386 (or ARM) machine code. Java is probably less popular. (And Java, by the way, is nearly as functional as Javascript.)
What would you describe as "Functional" then? i.e. What is the key difference between a Functional language and a language that has "Functional Aspects"? Show me the difference you believe is there and I'll show you the Javascript goods.
I'm not a dictionary, but I would say that "functional" is usually a synonym for "declarative". That is, a functional language is one in which work is done primarily by computing values, rather than by manipulating state. Javascript is designed primarily to manipulate the state of the browser, and internally most of its work is done by manipulating the state of objects, arrays and local variables. Therefore it is not a functional language.
In the limit, you have "pure functional" languages like Haskell, in which you can't manipulate state at all (at least, not without monads or uniqueness types or something like that).
However, Javascript has "functional aspects" in the form of closures, anonymous functions and higher-order functions, which are features common to (nearly?) all functional languages.
I saw the talk. The cube attack was very impressive: it allowed Shamir to break a fairly difficult-looking toy cipher (constructed, of course, to have an Achilles heel, but still probably impossible to break with other known techniques). He used only one bit per packet (with a million packets) and didn't use any particular knowledge of the cipher's internals.
However, as presented the attack probably only breaks toy examples. Its real-world applicability will depend on how well Shamir and Dinur manage to adapt it to ciphers which don't have this simple structure. For example, it will be difficult to apply the attack to either hash functions or block ciphers, because their iterated design tends to give them high degree. The attack will also be difficult to adapt because of its low tolerance for noise and its applicability to a narrow range of scenarios. Still, Shamir believes that it will be applicable at least to some modern stream ciphers, so I'll be keeping an eye out for the full version.
There was a rump session talk on Gpcode, actually. It was suggested that if you had enough porn and/or music on your computer (tens of thousands of files with known headers, I believe), an attack on RC4 would recover your disk. It's related to the attack that breaks WEP. I don't know if it's been implemented.
In mathematical terms, this makes Wikipedia a non-simply-connected space. No, it doesn't. In a simply-connected space, any path between two points is fundamentally the same. Non-simply-connected refers to a shape like a torus, in which getting somewhere by going clockwise and by going counter-clockwise are fundamentally different.
What it does mean, however, is that "Wikipedia distance" is not a metric.
We've mostly solved it further down the thread. The top section is in ternary (with 0 replaced by |||), 000-space, 001->a, 002->b, etc. It's strangely wrapped: the spaces and non-spaces at the beginnings and ends of lines count. It says "FRANK SHOEMAKER WOULD CALL THIS NOISE".
The second part we haven't deciphered yet. It's possible that we'd need a Fermilab insider for this.
The third part is RLL. Once you decode the RLL (number of | between consecutive ||), you get the same code as part one, which says "EMPLOYEE NUMBER BASSE SIXTEEN", or so I've been told. This suggests that at least one part of the puzzle requires help from Fermilab people.
My uninformed guess is that once we solve the middle section, we'll get someone's name. His or her employee number at Fermilab spells something out in base 16, a coincidence which Frank Shoemaker would call "noise". Another possibility is that the middle section is hex-encoded employee ID numbers, which would mean that we can't solve it.
It's actually simpler than that. Set it as |->1, ||->2, |||->0, and 001->a, 002->b etc, you get the same thing. I think you have to fix some wrapping issues where ||| is wrapped as | ||.
According to the reps at Thawte, if you are using a third party ssl cert (thawte, verisign, etc), this does not affect you. That sounds unlikely to me. The usual process to get a cert is to generate a public/private key pair and create a certificate signing request from the public key. The authority then signs the CSR and returns it to you. But you still generated the private key, so if you did it on Debian, you're still vulnerable. Maybe in some cases it's generated by Firefox, though... any idea if Firefox is vulnerable to this (i.e. does it link OpenSSL)?
As a security researcher myself, I sometimes wonder when difficult research that leads to exploits is the right thing to do. Of course, I think that most of the time it is, or I wouldn't be in the business, but this sort of story is still troubling sometimes.
Why isn't "what happened before" meaningful in either situation? In a strict sense, the question is meaningful and the answer is "nothing". (Or perhaps, "the FBI warning".) But the point is that while there's time and causality in our world, and also in the film, the two are not comparable to the point where you can say that some event in the real world happened directly before some event in the film.
I could easily demonstrate for Bugs Bunny what he is in our universe by creating something similar in his (we're of course operating under the assumption that Bugs Bunny is actually alive and his universe actually exists). That's because our world and Bugs' are relatively similar. There's no reason to believe that whatever mode of being God inhabits is that similar to ours. Also, there are plenty of passages in the Bible trying to explain the relation between God and humans.
As for "who created", it's just a bad analogy. Bugs asking who drew the animator is like a human asking "who's vagina did God come out of?". A human asking "who created God?" is like Mr. Bunny asking "who created the animator?", a perfectly sound question. No, the corresponding question to that would be "what stork delivered the animator?". "Creation" in the sense of the question (at least, as I understand it) is a more deliberate and controlled action, much like drawing (in fact, the Bible repeatedly draws analogies to sculpting).
But that's not even the point. The point is that if time and causality work differently for God, as the Bible suggests that they do, then our sense of "creation" might not carry over at all.
A supreme being who created the universe would be at least as complicated, and probably much more so. So how did the supreme being come about? Christians don't claim to know the answer. The question is probably wrong, and the answer, to the extent that there is one, probably isn't expressible in human logic or physics.
Consider a Looney Tunes animated film as a metaphor for the universe. Such a film is 2-dimensional, its "time" (measured in frames) is totally unlike the time in the outside world, the physics is mostly consistent but unlike real-world physics, etc. Bugs Bunny wants to know: what happened before the opening credits, and who drew the animator? (It must have been an even more complicated animator!)
The answer is completely outside his understanding. The animator is vastly more complex than a cartoon character, and he wasn't drawn at all. Nothing happened before the opening credits: the animator's world is outside the film, and the nature of time there is completely different.
Similarly, questions like "what happened before the creation of the universe" and "who created God" are not really meaningful.
Take your undirected graph, and write each undirected edge as two directed edges, one in each direction. You now have a directed graph. Run Dijkstra or Floyd-Warshall.
In other words, take all your two-way streets, and consider them as two one-way streets next to each other.
If it did let you seek to an arbitrary point, then wouldn't it be a block cipher rather than a stream cipher, by definition? If it let you seek to an arbitrary point, it would be a pseudorandom function. A block cipher is more: it's a pseudorandom permutation, and one whose inverse is efficiently computable. It's also less, in that the block size needs to be large enough for the amount of data you're encrypting. For instance, you shouldn't use Blowfish in counter mode to encrypt a hard drive, because its block size is too short and an attacker is likely to be able to learn (a tiny amount of) information about your disk's contents, regardless of the key length.
Shortest path is easily soluble in polynomial time. Dijkstra's algorithm works on directed graphs (such as street maps with some one-way streets), but not on negative edge-weights. There are other algorithms (such as Floyd-Warshall) that work on directed graphs where some edges are negative. What you might be thinking of is the "traveling salesman problem", in which you need to visit every vertex of the graph exactly once in the shortest distance.
A real-time media player might not be implementable in JavaScript, but a format converter certainly can. And how are you going to get at the music file, if it's encrypted with a key that's only present in your tamper-resistant TPM, which will only decrypt it when a Microsoft-signed copy of Super Hardened Trusted Secure Windows has been booted on unmodified Dude You Got A Dell hardware? What if it's only stored in a separate partition accessible through the Insect Overlord Hypervisor? What if the content of media files isn't even available through your namespace?
contain some exhaustive catalogue of "signatures" for all RIAA music They could just train it to recognize talentless, over-compressed*, formulaic pop music.
* Not compressed as in MP3, compressed as in "loudness wars".
Slashdot Mirror
I've never really understood the fundamental basis for this objection. It's inconvenient, it drains power on laptops, sure, but to me, those are annoyances and not fundamental flaws.
It's a minor annoyance for desktops. A minor one, but one that I shouldn't have to deal with. A constant reminder of DRM.
But it's more annoying for laptops. When I'm traveling, I don't want to take a cake box of CDs with me, but I often do want to play video games on the plane. What's more, my current laptop (a Thinkpad) doesn't even have a CD drive, so I'd have to bring a big honking external drive, and even that wouldn't work on a plane, because I'd need to power it.
I bought Spore. The DRM is irritating. But you don't need the cocking disc in the drive to play.
The idea is to set IO = ST RealWorld. Since you can only purify things of type (forall a . ST a), you still can't purify IO. On the other hand, you then don't have separate types for IORefs and STRefs, IOArrays and STArrays, and so on.
It'd be extra neat if they could do it with STM as well, but that seems unlikely. IORefs and STRefs are the same on the inside, but TVars are not, so it'd take some deep compiler hackery.
Thoughts on Haskell, from a Haskell programmer.
Haskell has a very nice software transactional memory library, which makes a lot of otherwise-difficult concurrency problems much easier. It's statically safe, too, unlike similar libraries for imperative/OO languages.
Certain other language features are very nice. Monads are also extremely powerful once you wrap your head around them, and the type-class system and standard libraries make a lot of math programming problems much easier.
The language also has downsides. The laziness makes it possible to build up an arbitrarily long chain of suspended computations, which amounts to a hidden memory leak. Laziness also complicates the semantics for "unchecked" exceptions, most notably division by zero. The combination of laziness and purity can make the language very difficult to debug and optimize. While the compiler has very powerful optimization capabilities, sometimes code needs to be just so to use them (like flagging things "const" or "restrict" in C), and this can make it hard to write clean code that runs fast.
The other problem is that most programs need some amount of imperative code somewhere to do the I/O. This code has a tendency to be verbose, nasty and slow in Haskell.
There are also some problems that would be relatively easy to solve in a very nice way within the semantics of the language (give or take), but are not solved well in the standard libraries. These include exception handling, global mutable state, strings and regular expressions, certain I/O operations, arrays and references. It would be very nice if the ST and IO monads were unified, and if references and arrays had nice syntax; this would reduce the ugliness needed to write those occasional bits of imperative code.
What this all means is that Javascript is the most widely deployed functional language in existence!
Javascript is probably the most widely-deployed programming language in existence. Nearly every PC, nettop and smartphone has at least one complete Javascript implementation on it, and many of them have more than one. The same is not true for any other programming language I can think of, unless you count i386 (or ARM) machine code. Java is probably less popular. (And Java, by the way, is nearly as functional as Javascript.)
What would you describe as "Functional" then? i.e. What is the key difference between a Functional language and a language that has "Functional Aspects"? Show me the difference you believe is there and I'll show you the Javascript goods.
I'm not a dictionary, but I would say that "functional" is usually a synonym for "declarative". That is, a functional language is one in which work is done primarily by computing values, rather than by manipulating state. Javascript is designed primarily to manipulate the state of the browser, and internally most of its work is done by manipulating the state of objects, arrays and local variables. Therefore it is not a functional language.
In the limit, you have "pure functional" languages like Haskell, in which you can't manipulate state at all (at least, not without monads or uniqueness types or something like that).
However, Javascript has "functional aspects" in the form of closures, anonymous functions and higher-order functions, which are features common to (nearly?) all functional languages.
I saw the talk. The cube attack was very impressive: it allowed Shamir to break a fairly difficult-looking toy cipher (constructed, of course, to have an Achilles heel, but still probably impossible to break with other known techniques). He used only one bit per packet (with a million packets) and didn't use any particular knowledge of the cipher's internals.
However, as presented the attack probably only breaks toy examples. Its real-world applicability will depend on how well Shamir and Dinur manage to adapt it to ciphers which don't have this simple structure. For example, it will be difficult to apply the attack to either hash functions or block ciphers, because their iterated design tends to give them high degree. The attack will also be difficult to adapt because of its low tolerance for noise and its applicability to a narrow range of scenarios. Still, Shamir believes that it will be applicable at least to some modern stream ciphers, so I'll be keeping an eye out for the full version.
There was a rump session talk on Gpcode, actually. It was suggested that if you had enough porn and/or music on your computer (tens of thousands of files with known headers, I believe), an attack on RC4 would recover your disk. It's related to the attack that breaks WEP. I don't know if it's been implemented.
It's also possible that they had a generator, and the gas or diesel fuel exploded.
I'm guessing that most of the customers are virtual-hosted, and therefore have only a fraction of a server, but some customers have many servers.
What it does mean, however, is that "Wikipedia distance" is not a metric.
Never mind about the wrapping. Anonymous is right: remove the line breaks, but preserve the anomalous spaces at the beginnings and ends of lines.
We've mostly solved it further down the thread. The top section is in ternary (with 0 replaced by |||), 000-space, 001->a, 002->b, etc. It's strangely wrapped: the spaces and non-spaces at the beginnings and ends of lines count. It says "FRANK SHOEMAKER WOULD CALL THIS NOISE".
The second part we haven't deciphered yet. It's possible that we'd need a Fermilab insider for this.
The third part is RLL. Once you decode the RLL (number of | between consecutive ||), you get the same code as part one, which says "EMPLOYEE NUMBER BASSE SIXTEEN", or so I've been told. This suggests that at least one part of the puzzle requires help from Fermilab people.
My uninformed guess is that once we solve the middle section, we'll get someone's name. His or her employee number at Fermilab spells something out in base 16, a coincidence which Frank Shoemaker would call "noise". Another possibility is that the middle section is hex-encoded employee ID numbers, which would mean that we can't solve it.
Awesome, did you email them?
It's actually simpler than that. Set it as |->1, ||->2, |||->0, and 001->a, 002->b etc, you get the same thing. I think you have to fix some wrapping issues where ||| is wrapped as | ||.
The first part is ternary, with 3 substituted for 0. It's somewhat miswrapped, but it appears to say "FRANK SHOEMAKER WOULD CALL THIS NOISE".
As a security researcher myself, I sometimes wonder when difficult research that leads to exploits is the right thing to do. Of course, I think that most of the time it is, or I wouldn't be in the business, but this sort of story is still troubling sometimes.
I told you not to touch that darn thing...
But that's not even the point. The point is that if time and causality work differently for God, as the Bible suggests that they do, then our sense of "creation" might not carry over at all.
Consider a Looney Tunes animated film as a metaphor for the universe. Such a film is 2-dimensional, its "time" (measured in frames) is totally unlike the time in the outside world, the physics is mostly consistent but unlike real-world physics, etc. Bugs Bunny wants to know: what happened before the opening credits, and who drew the animator? (It must have been an even more complicated animator!)
The answer is completely outside his understanding. The animator is vastly more complex than a cartoon character, and he wasn't drawn at all. Nothing happened before the opening credits: the animator's world is outside the film, and the nature of time there is completely different.
Similarly, questions like "what happened before the creation of the universe" and "who created God" are not really meaningful.
Dijkstra.
Take your undirected graph, and write each undirected edge as two directed edges, one in each direction. You now have a directed graph. Run Dijkstra or Floyd-Warshall.
In other words, take all your two-way streets, and consider them as two one-way streets next to each other.
Shortest path is easily soluble in polynomial time. Dijkstra's algorithm works on directed graphs (such as street maps with some one-way streets), but not on negative edge-weights. There are other algorithms (such as Floyd-Warshall) that work on directed graphs where some edges are negative. What you might be thinking of is the "traveling salesman problem", in which you need to visit every vertex of the graph exactly once in the shortest distance.
* Not compressed as in MP3, compressed as in "loudness wars".