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One of the main differences is that Message Authentication Codes don't prove authorship of the message. Imagine the situation, when Bob sent a signed contract to Alice. In case of digital signature Alice can go to court claiming that Bob has signed the contract. A judge can verify the signature and make sure that the contract was really signed by Bob as only ...


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In short words: when you compute things modulo $n = pq$, you are really computing things simultaneously modulo $p$ and modulo $q$. That's the gist of the Chinese Remainder Theorem. So to prove that $a = b \pmod n$, you just have to prove that $a = b \pmod p$ and $a = b \pmod q$. Modulo $p$, for any $x$ that is not a multiple of $p$, $x^{p-1} = 1 \pmod p$ ...


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Is javascript RSA signing safe? …is safe or can people forge… In contrast to the accepted answer, I would not call it “safe” from a cryptographic point of view and I would definitely not say that “ if you take good care of securing your environment where you run the JS code you will be OK. ” because the sad fact is: that’s not enough to ensure ...


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(Q1) Assuming that you talk about the size of the secret key elements which equals the input size of the OWF when you talk about the "input", this should be at least as much as the output size. Consider a function $f: \{0,1\}^m \rightarrow \{0,1\}^n$.The thing to worry about when you choose $m < n$ is a brute force search for a preimage, which in this ...


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Yes, this seems to make sense and it is a plausible solution. The KEM approach does not work, unless you use some tricks, like including a hash of the message in the KEM. (That could work, of course.) Security goal The type of scheme we are looking at consists of three algorithms $(K,E,D)$. The key generation algorithm $K$ outputs two keys, say $k_0$ and ...



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