CODEWITHSUNDEEP
encryptioncompression
wxi
wxi

Reputation: 7

Compression or encryption?

I got a file that seems to not have anything readable into it (for a human)

How can I be sure that it hasn't anything readable for a human? Because it's way too large to read it entirely (maybe a program that searches for words or entropy or I don't know.)

How can I know if this file is compressed or encrypted, or both? And is it possible that it has a proprietary compression so I can't distinguish it from encryption?

Because if I can make sure that it's encrypted, I can stop my work directly, but if it's just encoded/compressed, maybe I can find a way to read it

(I tried to compress it with the basic Windows archiver and it loses 18% of its size. Does it mean that it's not encrypted? Does an encryption permit that much compression?)

Upvotes: 0

Views: 259

Answers (2)

Mark Adler
Mark Adler

Reputation: 112189

Yes, it is certainly possible to create a compression format for which all possible sequences of bits is valid. In that case, you would not be able to distinguish the compressed data from random or encrypted data.

I am not aware of a commonly implemented compressed format that has that property. You could try all of the decompressors you can find on the data to see if any continue to decompress through all of the data without erroring out. You can also try starting at different locations in your data, since there may be some sort of header before the compressed data.

Upvotes: 1

Theodore
Theodore

Reputation: 303

Online Decryption

If you would like to decrypt the file. You could simply copy and paste everything inside of https://online-toolz.com/tools/text-encryption-decryption.php

that feature can decrypt messages fast.

Encoder & Decoder

https://www.base64decode.org/

I found this website a while ago, this website is trusted and fast with great reviews. This method can also help with your request.

Upvotes: 0

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