• Re: Naive PRNG encryption?

    From Rich@21:1/5 to vallor on Sat Aug 3 20:00:36 2024
    vallor <vallor@cultnix.org> wrote:
    I saw someone mention this on another 'froup, and I've thought about it myself. Is it really "uncrackable"?

    Take a plaintext and transform each character with the output
    of a PRNG, with the seed being the key.

    https://web.pa.msu.edu/reference/pgpdoc1.html

    When I was in college in the early seventies, I devised what I
    believed was a brilliant encryption scheme. A simple pseudorandom
    number stream was added to the plaintext stream to create
    ciphertext. This would seemingly thwart any frequency analysis of
    the ciphertext, and would be uncrackable even to the most
    resourceful Government intelligence agencies. I felt so smug about
    my achievement. So cock-sure.

    Years later, I discovered this same scheme in several introductory
    cryptography texts and tutorial papers. How nice. Other
    cryptographers had thought of the same scheme. Unfortunately, the
    scheme was presented as a simple homework assignment on how to use
    elementary cryptanalytic techniques to trivially crack it. So much for
    my brilliant scheme.

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  • From =?UTF-8?B?8J+MiPCfkpDwn4y78J+MuvCfj@21:1/5 to All on Sun Aug 4 09:52:04 2024
    On Sat, 3 Aug 2024 20:00:36 -0000 (UTC), LO AND BEHOLD; Rich <rich@example.invalid> determined that the following was of great
    importance to Rich <rich@example.invalid> and subsequently decided to
    freely share it with us in <v8m294$3jnbf$1@dont-email.me>:

    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= vallor <vallor@cultnix.org> wrote: =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= I saw someone mention this on another 'froup, and I've thought about it
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= myself. Is it really "uncrackable"? Take a plaintext and transform each
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= character with the output of a PRNG, with the seed being the key.
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?=
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= https://web.pa.msu.edu/reference/pgpdoc1.html =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?=
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= When I was in college in the early seventies, I devised what I
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= believed was a brilliant encryption scheme. A simple pseudorandom
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= number stream was added to the plaintext stream to create
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= ciphertext. This would seemingly thwart any frequency analysis of
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= the ciphertext, and would be uncrackable even to the most
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= resourceful Government intelligence agencies. I felt so smug about
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= my achievement. So cock-sure. =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?=
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= Years later, I discovered this same scheme in several introductory
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= cryptography texts and tutorial papers. How nice. Other
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= cryptographers had thought of the same scheme. Unfortunately, the
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= scheme was presented as a simple homework assignment on how to use
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= elementary cryptanalytic techniques to trivially crack it. So much for
    =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?= my brilliant scheme. =?UTF-8?B?8J+Ps++4j+KAjfCfjIg=?=

    Lots of Dunning Kreuger to share...

    --

    "I think we should destroy every last fucking mosque in America." - "Checkmate, DoW #1" <Lunatic.Fringe@The.Edge> proves for us that white males are violent in Message-ID: <MPG.32c5bfefd18c9a698f0a8@news.altopia.com>

    "Yeah, but you think everybody's Greg. There are a couple people here who can't resist responding to everything the aSSwurm or the Pussy Willow says. It does me no good to plonk aSSwurm and Pussy Willow if I still have to wade through a hundred inane
    posts a day involving those two assholes, so now I've plonked the chronic responders as well. They'll figure it out, and then they can make a choice... exchange stupid drivel with those two, or have more intelligent and interesting conversations with me.
    I know damned well Greg got sick of all that shit, and now I'm sick of it too. Those who choose to get led around by the lowest common denominator are fucking up AC and every other group they play that game in. If that's the kind of Usenet they want,
    they can wallow in the same slop as the two retards elsewhere, because they're only contributing to fucking this group up too. I can take or leave this shit, because I have plenty to keep me occupied with my room addition project, and it's a hell of a
    lot more rewarding than exchanging baby talk with the likes of the aSSwurm. May his fucking worthless AIDS-infested carcass drop fucking dead ASAP and quit wasting oxygen. To sum it up, talk to those two idiots elsewhere, or they'll probably be the only
    people left to talk to here." One can only presume that Jim and Creon/Vallor have solved this problem and are together in a private chat "having more intelligent and interesting conversations" instead of these "Civil" calls for shunning and
    authoritative control of discussion. As Seen on TV : <MPG.35cd7d50e1b224b1994604@news.altopia.com>

    "I'm pretty sure all gods are fictional, I'm smart enough to not proclaim I know this." - Kwills is only smart enough to doubt himself while arguing that a belief in imaginary made-up gods can't just be ignored as "mental illness" in <
    mo4q0j9tcqjt68s039loiacrbarihsh9i5@4ax.com>

    "If you worried half as much about your own personal life as you do everyone else's, you might almost be tolerable, obsessed stalker." -James "Checkmate" Gorman, in perhaps the most ironic and mentally-challenged statement ever made on Usenet. <MPG.
    4001ba2c14cace6c98cb6f@usnews.blocknews.net>

    "Trying to diminish others doesn't make you look any better. In fact, it does quite the opposite. Why are you always so bitter and angry? Do you have AIDS or something like so many other tranny girls do?" -James "Checkmate" Gorman in <MPG.
    405409befd41f28898969d@test.blocknews.net>

    "You should see my archive on you" -James "Checkmate" Gorman teases us with his "dosser" in <MPG.3eea81b23145043b98c338@usnews.blocknews.net>

    "Sorry, nothing to see here. The joint wasn't as bad as they say, but I'm not looking to go back. I'm a model citizen, clean as a whistle. I've owned my own home for 12 years, owned my own business almost as long, don't bother anyone and they don't
    bother me. You have nothing in any "police report" pertaining to me. Don't you think they would have "come a-knockin" a long time ago if they had any reason to? You're delusional and paranoid, and I have to wonder why.

    Oh... I should mention that there are a LOT of trannies in prison. I don't know why, but there are. The State even has to give them hormone shots for their tiddies at taxpayer's expense, and they wear bras and panties. I found everything about them
    revolting. That's why the whole "Bubba" thing is almost completely a myth, except in cell living. That shit wouldn't fly in a 100-man dorm, but trust me, those little trollops find ways to serve the willing when the lights go out. You see something, you
    keep your mouth shut about it because that way you don't get in a wreck. I never partook in such activities because the whole idea is just repulsive. I think that's a big part of what I don't like about you. I've seen how they act and I've talked to a
    few... total drama queens in every sense." -James "Checkmate" Gorman reminisces about prison in <MPG.3ceb37c2eddbaff98b07a@usnews.blocknews.net>

    "Not true. I've seen square waves on the oscilloscope from some certain generator. Square waves can be created from other than sine waves. Sine waves aren't everything (or anything you sick pervert %), I think that's the point you are missing. -
    Mathemagician "Lane Larson" in <939d6741-df96-5f2e-a444-b6dfd77de09e@stoat.inhoin.edu> seems to argue that square wave generators must use Fourier transforms "of course" to generate "almost" square waves... in his feeble attempt to quash my assertion
    that "square waves do not exist in reality" in post <=3D?U=3D?UTF-8?Q?T?=3DF-8?Q?=3DF0=3D9F=3D8C=3DBA?=3DKWuXdYTXCQ5ApC$@88.203.236.221=3D?U=3D?UTF-8?Q?T?=3DF-8?Q?=3DF0=3D9F=3D8C=3DBA?=3D>.

    "Colour me fanboi, oh yes indeed. I'm a fanboi who is proudly content to be just that." - snipeco.2@gmail.com (Sn!pe) in <1qx4ikk.c8jzw919si6cmN%snipeco.2@gmail.com>

    Golden Killfile, June 2005
    KOTM, November 2006
    Bob Allisat Memorial Hook, Line & Sinker, November 2006
    Special Ops Cody Memorial Purple Heart, November 2006
    Special Ops Cody Memorial Purple Heart, September 2007
    Tony Sidaway Memorial "Drama Queen" Award, November 2006
    Busted Urinal Award, April 2007
    Order of the Holey Sockpuppet, September 2007
    Barbara Woodhouse Memorial Dog Whistle, September 2006
    Barbara Woodhouse Memorial Dog Whistle, April 2008
    Tinfoil Sombrero, February 2007
    AUK Mascot, September 2007
    Putting the Awards Out of Order to Screw With the OCD Fuckheads, March 2016

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  • From vallor@21:1/5 to All on Sat Aug 3 10:41:41 2024
    I saw someone mention this on another 'froup, and I've thought about it
    myself. Is it really "uncrackable"?

    Take a plaintext and transform each character with the output
    of a PRNG, with the seed being the key.

    How easy is it to crack the resulting "ciphertext"?

    --
    -v

    --- SoupGate-Win32 v1.05
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  • From Phil Carmody@21:1/5 to vallor on Wed Aug 21 20:56:46 2024
    vallor <vallor@cultnix.org> writes:
    I saw someone mention this on another 'froup, and I've thought about it myself. Is it really "uncrackable"?

    Take a plaintext and transform each character with the output
    of a PRNG, with the seed being the key.

    That's just a stream cypher.

    How easy is it to crack the resulting "ciphertext"?

    If you have more than one encrypted with the same key, probably pretty
    easy, depending on the transform. Just "subtract" (the inverse of the transform) the two streams from each other, and you'll end up with the difference between the two plain-texts, which will be highly non-uniform.

    Phil
    --
    We are no longer hunters and nomads. No longer awed and frightened, as we have gained some understanding of the world in which we live. As such, we can cast aside childish remnants from the dawn of our civilization.
    -- NotSanguine on SoylentNews, after Eugen Weber in /The Western Tradition/

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