• wizardbeard@lemmy.dbzer0.com
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    12 hours ago

    Sounds like a good case for brute forcing the filenames. Just do the proper thing and don’t leave your cloud storage publicly accessible.

        • FooBarrington@lemmy.world
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          9 hours ago

          A UUID v4 has 122 bits of randomness. Do you know how long that would take to brute-force, especially with network limitations?

          • 𝕸𝖔𝖘𝖘@infosec.pub
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            9 hours ago

            It taking a long time doesn’t make it an impossibility. The fact that it has a limit of 122 bits, in and of itself, makes the possibility of a bruteforce a mathematical guarantee.

            • bamboo@lemmy.blahaj.zone
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              7 hours ago

              By this logic, all crypto is bruteforcable, on a long enough timeline.

              A 122 bit random number is 5316911983139663491615228241121378303 possible values. Even if it were possible to check 1 trillion records per second, it would take 168598173000000000 years to check all the UUIDs and get the info on all the users. Even if every human on earth signed up for the app (~8 billion people), and you wanted to just find any one valid UUID, the odds of a generating a UUID and that being valid in their DB is basically 0. You can do the math your self following the Birthday Paradox to determine how many times you would need to guess UUIDs before the probability that any one UUID is valid against a population of the whole world is greater than 50%.

              • 𝕸𝖔𝖘𝖘@infosec.pub
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                7 hours ago

                You should read into the NSA’s Translator. Granted, it’s relatively outdated with shifting text algorithms, but for a very long time (about half a century), it was able to bruteforce any key, regardless of length, in under an hour.

                • bamboo@lemmy.blahaj.zone
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                  7 hours ago

                  I’m not familiar with NSA’s Translator, so any info would be appreciated.

                  I saw your other comment about DES, and it should be noted that DES was with a key length of 56 bits, and that was enforced precisely because the NSA could brute force it. It wasn’t even a secret they could brute force 56 bit encryption, and written into law. Back then, if you wanted to use more than 56 bit encryption in the United States, you had to provide a key escrow system to allow the government to decrypt the content if they needed to. Around the 2000s with the rise of e-commerce, they dropped the export restriction because it was doing more harm than good. No one wanted to use so few bits in the encryption keys, but it was illegal at the time to write software which did.

                  A UUID’s 122 bits of randomness are exponentially more than the 56 bits DES offered. My original point being, all crypto is inherently brute forceable on an infinite timescale, but key length and implementation decisions are chosen to so that it would be computationally infeasible to brute force.

                  • 𝕸𝖔𝖘𝖘@infosec.pub
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                    6 hours ago

                    The Translator was the nickname given to, what essentially was, the NSA supercomputer that could solve any (non-shift text) encryption by bruteforcing the key in under an hour (most of the time, in about 15 minutes). I mentioned DES, because it was an encryption so old that nearly everyone has heard about it, and one that I know was used on The Translator. And you’re right, DES was capped at 56 bit keys, because they could crack it without The Translator, if needed.

                    But the scope isn’t if the UUIDs are crackable (which, of course, they’re not, since they’re not encrypting anything). The scope is if using UUIDs as filenames in this publically accessible db a good way to hide the files. And the answer is: no it is not a good way, because a computer powerful enough can guess all possibilities in a matter of minutes, and query them all against the db to discover all files stored within.

              • 𝕸𝖔𝖘𝖘@infosec.pub
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                8 hours ago

                It’s not, though. And thinking that it is impossible is why DES, for example, was “translatable” by the NSA for decades. Never assume something is impossible just because it’s difficult.

                • Grendel84?@tiny.tilde.website
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                  6 hours ago

                  @01189998819991197253 @ConstantPain

                  Security isn’t binary, it’s a spectrum. You apply the level of security that is appropriate for each situation.

                  Of course it’s *possible* to brute force it, but by the same logic you could brute force jwt tokens, or api keys, or even ssl certs.

                  It’s literally *impossible* to apply “max security” to everything, so you have to prioritize.

                  What happened was unconscionable, but insisting uuid are mathematically breakable isn’t helpful, and can make it worse.

                • Constant Pain@lemmy.world
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                  6 hours ago

                  It is. It is practically impossible to guess the file names. You telling otherwise means you don’t have sufficient knowledge on the matter.

                  • 𝕸𝖔𝖘𝖘@infosec.pub
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                    7 hours ago

                    The scope isn’t if they’re crackable (which, if course, they’re not, since they’re not encrypting anything). The scope is if using UUIDs as filenames in this publicaly accessible db a good way to hide the files. And the answer is: no it is not, because a computer powerful enough can guess all possibilities in a matter of minutes, and query them all against the db to discover all files stored within.