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/sci/ - Science & Math

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3493979 No.3493979 [Reply] [Original]

/sci/ I really need your help, I want to know exactly what operations take place in a system where a number is fetched and after some operations a totally new "encoded" number is generated. I want to be able to convert the "encoded" numbers back to normal, without knowing its decoded value, of course.

For example if I fetch the following number:
5471460063830707
It becomes:
6904464302768518

I have entered 3 different sets of numbers into the system, and recolected the resulting data here:
https://spreadsheets.google.com/spreadsheet/ccc?key=0AnoPOYjA7T3SdHV4WkJ6WU5kQUpraWg3SFJGYXBZTFE#gid
=0

How do I find out exactly what operations are taking place, so I can decode the numbers without knowing their normal value --
i.e. converting an "encoded" number back to "normal", using the data I collected?

>> No.3494105
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3494105

shameless self bump

>> No.3494130

Unless this is a common encryption or a fairly simple mathematical operation, I doubt you will be able to find a pattern of mathematical operations with any feasible amount of data.
>see: md5

>> No.3494149

>>3493979
wtf is with the image, is that supposed to scare me from masturbating?

>> No.3494163

>>3494149

Its intended to reveal the truth.
You know it very well to be true.
You were once amazing, and then you started doing it, and soon enough here you are!
On 4chan, the abyss of the internet!

>> No.3494275
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3494275

>>3494130
It's not encrypted using complex math -- and it's definitely not a hash., its probably just a fixed mathematical operation, if you change a few digits in a certain position the entire encoded number is not affected as a whole, just a small part.

However I still haven't been able to find an accurate numeric relation that could be used to decode them:

i.e. calculating the difference between 2 different encoded values, and finding a direct relation between this difference to find out the exact result.

In case that I do actually need a bigger chunk of data, about how many examples do I need? And what is the best strategy to spot the patterns?

i.e. subtract 1 in position 16, then subtract 1 at position 15, etc etc..

>> No.3497673

last bump

>> No.3497691

You're talking about cryptanalysis, OP.
http://en.wikipedia.org/wiki/Cryptanalysis

If you don't know what kind of encryption algorithm was used, then I'm afraid you're out of luck, because the techniques for identifying the encryption are probably beyond your interest and ability.

>> No.3497762

>>3497691
Yeah, I understand the basic notions of it, but I was trying to use simple math and logic to find out the patterns in the encoding, the number itself doesn't look like a hash or an encrypted string, because the numbers were just replaced with other numbers and vary only from 0 to 9, so it would be a lot easier to understand because it doesn't use the whole alphabet or special characters.

Just thought that someone could notice a pattern there that I was missing, but it's definitely not complex encryption.