CODEWITHSUNDEEP
hashencryption
Gontham
Gontham

Reputation: 33

Number only Hash or Cipher decrypt

I wanted to know if it's possible to derive a method to generate a cipher or Hash if I have a large data sample of the ciphered text and it's corresponding ASCII text.

An example of the ciphered text is: 01jvaWf0SJRuEL2HM5xHVEV6C8pXHQpLGGg2gnnkdZU= That would translate to: 12540991

the ASCII text contains only numbers.

I would think it is possible, since we're dealing with only numbers and I do have a sample of the ciphers and their ASCII translations. But I am not sure where to start looking, or maybe I am wrong and such a thing is not possible.

What do you guys think ?

Upvotes: 1

Views: 838

Answers (2)

Samy Vilar
Samy Vilar

Reputation: 11130

If you are trying to derive the original algorithm that generated the hashes of a giving set of values and hashes, you could try mainstream algorithms and see if you get any hits, if not it maybe impossible or simply take to much time to find, the most common homegrown algorithms tend to be a combination of a world wide salt + unique random salt + multiple iterations of a common hashing function SHA256.

If you are trying to invert a mainstream hashing functions, that would be impossible, there one way functions, you can't find the original text giving the hash value, if you still want the original text you would need to iterate over all the possible values to determine which generated that hash, being that its numbers it isn't that bad, just build up a look up table using which ever algorithm was used, the hash would be key and text that generated that hash would be the value, one done simply look up the hash to find the original text. This is called an online attack.

Upvotes: 1

Todd A. Jacobs
Todd A. Jacobs

Reputation: 84443

What you're describing is what's called a known-plaintext attack. This is a form of cryptanalysis, so it is certainly possible, although good one-way hash algorithms are designed to be resistant to it.

While it's possible, it is unlikely to be practical against well-known hashing algorithms unless you are an expert in cryptography and an experienced code-breaker--and even then, it's not what one might call a short-term project.

A homegrown algorithm or simple encoding scheme is another matter, of course. If your question is "Is it possible?", then the answer is "Yes."

Upvotes: 1

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