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Encryption Security Math Technology

NIST Opens Competition for a New Hash Algorithm 187

Invisible Pink Unicorn writes "The National Institute of Standards and Technology has opened a public competition for the development of a new cryptographic hash algorithm, which will be called Secure Hash Algorithm-3 (SHA-3), and will augment the current algorithms specified in the Federal Information Processing Standard (FIPS) 180-2. This is in response to serious attacks reported in recent years against cryptographic hash algorithms, including SHA-1, and because SHA-1 and the SHA-2 family share a similar design. Submissions are being accepted through October 2008, and the competition timeline indicates that a winner will be announced in 2012."
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NIST Opens Competition for a New Hash Algorithm

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  • by rock217 ( 802738 ) <slashdot@rockBAL ... com minus author> on Friday November 09, 2007 @03:16PM (#21299135) Homepage Journal
    Encryption implies that you can reconstruct the original string from the encoded. Methods like md5, sha1, etc are one way algorithms that cannot be reversed* in a realistic amount of time.



    * - Rainbow tables
  • by HomelessInLaJolla ( 1026842 ) * <sab93badger@yahoo.com> on Friday November 09, 2007 @03:36PM (#21299413) Homepage Journal
    Crude hash:

    Take a full stalk from the marijuana plant--bud, leaves, and all. Strip the bud and the leaves away from the bulk fiber stem. Discard the stem. Roll and crush the bud and leaves together. Compress, twist, and tear. Compress, twist, and tear. Wring the water out of the bulk pulp. Leave the bulk pulp to demoisturize (not dry completely). This is the crudest form of hash and probably the oldest form known to man.

    Leftover hash:

    Take just the leaves from the marijuana plant. Repeat the process described for crude hash. Use the marijuana buds for normal smoking or cooking. This method allows one to make use of the leaves as well as the bud in separate form.

    Crude chemical extract:

    Take the buds from the marijuana plant. Break them apart but do not crush or damage the glands (trichomes). Place the broken up buds in ice water, swirl and mix, and scoop out the material which rises to the top. Dry gently (air dry, no heat).

    Supercritical chemical extract:

    Take the buds from the marijuana plant. Break them apart but do not crush or damage the glands (trichomes). Pack the material into a sealed cylinder. Attach a tube of compressed butane to the sealed cylinder. Discharge the butane through the sealed cylinder. Collect the effluent and allow the butane to evaporate (air dry, no heat).

    Sohxlet extract (honey blond hash oil):

    Obtain a sohxlet extraction apparatus. Use the buds, possibly the leaves, maybe even the stems from the plant. Extract for at least five cycles using pentane, hexane, or heptane. Collect and dry the extraction solution (air dry, preferably with attached vacuum, as little heat as possible). This is the finest hash oil you'll come across.

    In all cases avoid temperatures over 50C. The desireable components, technically, boil around 110-120C but significant amounts may be lost at temperatures over 50C.

    ENJOY!

    The point of making hash is to denature the typical plant products, such as chlorophyll, and extract them into a water layer (which is removed) or to extract the desireable hydrophobic products away from the bulk plant material. Smoking untreated or uncured marijuana plant material is somewhat flavorful (depending upon personal taste) but usually causes a digestive or nervous reaction (tummyache or headache).
  • by TechyImmigrant ( 175943 ) * on Friday November 09, 2007 @03:47PM (#21299575) Homepage Journal
    When hashing a data set larger than the resulting digest, it cannot be reversed at all. However you can find collisions which is handy if you want to subvert the PKI hierarchy that protects web transactions.

  • by lgw ( 121541 ) on Friday November 09, 2007 @04:07PM (#21299877) Journal

    1) That the NSA is so amazingly far ahead of everyone else in crypto that they were able to find something in AES that no one else has in over a decade.
    When the DES standard was created, the NSA was so amazing far ahead of everyone else that they were able to find somehting in DES that no one else found for over a decade. The NSA provided very specific technical advice (without explanation) that was followed in the creation of DES. Many years later, the rest of the world caught up and discovered that the NSA had corrected a very subtle weakness in DES.

    The NSA has an actual track record here, and their motives have proven good so far. However, they claim that (due to lack of funding and too much competition from financial firms for math PhDs) they aren't so far ahead any more.
  • by Llywelyn ( 531070 ) on Friday November 09, 2007 @04:13PM (#21299969) Homepage
    It is worth emphasizing that the NSA has said that AES 128/192/256 can be used to protect information up to the secret level, and that top secret information can be secured with AES 192 or 256. That's a pretty strong statement coming from the NSA, which if acting rationally they would not want to leave weaknesses in something that is used to secure information that would be, by definition, "very damaging to the US and its interests if released."

    Now, it is possible that such statements are just for show, but it takes a belief that they are playing an incredulously deep game that they would make those statements as a denial and deception practice.
  • Re:No, you're right. (Score:4, Informative)

    by smallfries ( 601545 ) on Friday November 09, 2007 @05:25PM (#21301013) Homepage
    Maybe you should chase the etymology one level deeper. If the original data cannot be recovered then it is not "hidden" but "destroyed". You may not believe that the term encryption means a two-way process with an available decryption function - but that is the definition that the crypto community uses, and so it's good enough for me.
  • by flosofl ( 626809 ) on Friday November 09, 2007 @05:54PM (#21301445) Homepage

    One very simple attack was changing the grades in a school system. The school encrypted the grades, so they thought they were safe from change. The failed students hacked into the system, and just changed their data to the same data held against students they knew had done well. Anyway, that's just one way that encryption doesn't protect you against malicious modification. It gets a lot sneakier the more you look into it.
    What was the school using, ROT13? It sounds like they were using a substitution cipher not a modern algorithm. If they had been using any kind of real encryption, there would be no way that technique would be possible. Some of the tests that modern encryption algorithms have to face are frequency analysis (which substitution ciphers fail) and known plain text attacks (I assume the students had access to the encrypted txt and their real information). Other than the school using a centuries old, easily defeated technique I call bullshit.

    Modern encryption *does* protect you from malicious altering of information. I encourage you to read up on Message Authentication Code [wikipedia.org] (and all it's sundry relatives, UMAC, HMAC, CMAC). By changing just one character in an encrypted block, you have just caused the MAC to show a mismatch and invalidate the integrity and authenticity of the data. Unless they have the key used for encryption (which would raise the question of why they simply substituted characters in an encrypted field), they are shit out of luck trying to fool anyone. Yes, the cipher block is useless, but no one will be "tricked" by the changed grade, either.
  • by James Youngman ( 3732 ) <jay&gnu,org> on Friday November 09, 2007 @07:06PM (#21302359) Homepage

    If the NSA really is so good that they can outdo the entire rest of the crypto community, well then they can probably break pretty much any of the cryptosystems out there.
    Actually I think you're right, but to play Devil's Advocate for a moment, I will note that the UK government agency GCHQ [gchq.gov.uk] developed a public-key cryptosystem between 1969 and 1973 [uni-klu.ac.at], significantly before Diffie and Hellman's (apparently) ground-breaking paper. So, government agencies are quite capable of beating the public state of the art and not telling anyone about it.
  • Oh no doubt (Score:3, Informative)

    by Sycraft-fu ( 314770 ) on Friday November 09, 2007 @11:01PM (#21303959)
    And there's evidence that the NSA understood quite a bit more about cryptography back in the DES days based on a change they made ot it that hardened it against an as of yet unknown kind of attack.

    However being a bit ahead in terms of creating a system is real different form being far enough ahead to break systems. To mistrust the NSA on AES means you figure that they know enough to know how to break it, and that they figure the knowledge is so far advanced that no one else will figure it out. One of the NSA's jobs is actually "To achieve information assurance for information infrastructures critical to U.S. national security interests." They are tasked with things like making sure that US financial systems aren't broken in to, hence things like DES/AES. As such if they knowingly allowed a breakable cryptosystem to become the standard and it was in fact broken, they'd have failed in that and have shit to answer for.

    So while I certainly believe they are the best in the business, and while I'd not be surprised to discover they know things that public does not, it would imply a staggering advance in cryptography for them to be able to break AES and figure that the public can't. In fact, it would probably imply something along the Tom Clancy lines of a computer that could break ANY machine based cypher and as such no matter what crypto you used short of a one time pad, you'd be screwed.

    I just don't find it reasonable to believe that. I find it more reasonable to believe that since good crypto is out there anyhow, and since their job is to protect US interests, that they did an honest analysis of AES and found it to be highly secure, just as everyone else did.
  • by Comatose51 ( 687974 ) on Friday November 09, 2007 @11:37PM (#21304109) Homepage
    Rainbow tables won't help you get the old message back since pretty much by definition or pigeonhole theorem there is more than one plaintext that can generate the same hash. Breaking a hash algorithm usually involves finding a plaintext that generates the specific hash, thus fooling the victim into thinking that plaintext was the original one.

    Or imagine this: you have a simple hash function that takes all the letters in a message, turns them into number based on their place in the alphabet, and adds them up to generate the sum. If that sum goes over 10,000 then it would do a mod 10,000 to wrap it around. There's an infinite number of plaintexts that can generate the exact same hash based on this hash algorithm. However, what you can never do is figure out which specific one generated it.

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