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Fastest method of CNF equation solution verification

You are asking about the algorithmic complexity of verifying a SAT solution with m clauses. Obviously if n is fixed and small, you can verify any solution in O(1) time-- just use a lookup table! So, ...
9 votes
Accepted

Does "SHA-256/192" use different initial values from SHA-256?

No, it is just the truncated as mentioned in NIST SP 800-208 $\operatorname{SHA-256/192}(M)$ $T_{192}(\operatorname{SHA-256}(M))$, the most significant (i.e., leftmost) 192 bits of the SHA-256 hash ...
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2 votes
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PKCS#7 SignedData - how is the "encryptedDigest" constructed for RSAES‐PKCS‐v1_5?

ITU may provide information about PKCS (and CMS) but they are not the author. PKCS7 (like all PKCS) was originally from RSALabs and now remains available as rfc2315; several versions of CMS -- which ...
4 votes
Accepted

Merkle–Damgård construction - the bigger input, the longer time to compute hash?

That's right, and you've just stated the obvious. The processing time of Merkle-Damgaard-based hash functions are proportional to the size of the input (unless the input is too small). That's also ...
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1 vote

SHA256 - alternative algorithm to receive same hash?

In my opinion, it depends on what you mean by “another” (ie. “different”) algorithm. Here are two algorithms. Each one takes a number as input, and produces a new number as output: (1) Take input ...
1 vote

SHA256 - alternative algorithm to receive same hash?

Due to the pigeonhole principle, any random function will eventually produce collisions with any other random function. After all, there are far more possible inputs than there are possible outputs (...
  • 13.8k
2 votes
Accepted

Create a control hash string from different sources, is there a difference, advantage or disadvantage in comparison when using this ways?

Assuming that there is no difference in files and strings (we will use $s_1$ and $s_2$), we can look at the hasing speed and pre-images and collision attacks. We assume + as concatenation summation ...
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