15b44600cb0f32739a1fe0b769a59d9e9642e287

A hash consists of 40 characters, and how to determine its encryption algorithm? And is it even possible to know its original value?

  • not. This is usually an irreversible process. but if there is a powerful stack of computers, then in principle, spending from day to month you can think of picking up :) - Artem
  • Only now, will the matched bytes be equal to those from which the hash is obtained? - avp
  • It is logical :) - Artem

3 answers 3

How to determine its encryption algorithm

  1. Not an encryption algorithm, but a hashing algorithm, are two different things;
  2. if you are sure that this data is the result of the hashing function, you can search for all known and see which output is the same number of bytes; if this message is a 2x / 3x concatenation, etc., then you will not be able to determine the hashing algorithm;
  3. the initial value can be found only by direct enumeration of all possible combinations.

The essence of the hash function is to get the value of the function y = f(x) such that, having "y" , it is impossible to recognize the "х" . Therefore, the task itself of finding the "x" by "y" rather complicated, because, as colleagues have already noted, there is no guarantee that the output of the function will not have the same value for two different "x" .

    You can and even as you can. It all depends on many factors, if the hash is compiled without salting and without reusing hashing (that is, hash from hash) and the algorithm is more or less known such as SHA-1 or MD5, then it is quite possible to split it in a couple of days. Take a look at the anti -forum forum - there are even contests for opening hashes.

    • In fact, you are talking about the selection of a password. But hash is often used to accelerate data retrieval. In this context, selection ("splintering") does not make sense. - avp
    • it turns out that the hashing algorithm itself is not secret, for a particular case, i.e. if this is a jvm hashing function, then there probably is one algorithm, and the known one, from here you can figure it out, but you can hardly reproduce it again ... - Gorets
    • one
      Yes, the point is that the hashing algorithm is not secret, everyone knows it, moreover, it is often its openness that allows the public to expose it to numerous strength tests. which in turn affects its security. because experts have the opportunity to analyze the algorithm and point out weaknesses - jmu
    • one
      The meaning of the hash is its ambiguous reversibility. It is as if there is a number 4, then it is very difficult to determine as a result of what operations it is very difficult or 2 + 2 or 6-2 or 2 * 2. If the algorithm is known, then restoring is already easier, but still difficult and ambiguous. Reversing a hash will result in a set of values. Suppose, as in the case with the number 4, the admissible algorithm is known: obtained by adding 2 single-digit numbers. Then the set of infinite values ​​will be reduced to 3 variants: 0 + 4, 1 + 3 and 2 + 2 - Barmaley

    Try the Hash Identifier utility. For me, determined in 100% of cases.