Myria
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Could Riemann hypothesis solve certainly RSA?
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7 votes

It's not that proving the Riemann Hypothesis would itself lead to a breakthrough against RSA. Rather, it's speculation that the methods leading to the discovery of a proof of the Riemann Hypothesis ...

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Can you decode aes by hand if you have the key?
5 votes

It would take you a while, but yes. You'd have to print out several tables that calculate things for you like $GF(256)$ field multiplication and inversion, but you could do it. It would be slow and ...

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Forging RSA1024 signature with e=3 where hash is right justified
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5 votes

When $\gcd(e, \phi(n)) = 1$, integers modulo $n$ coprime to $n$ have a unique $e$th root modulo $n$. This is the basis of RSA. Unlike for an unfactored RSA modulus, $\phi(2^{160})$ is easy to ...

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Constant time implementations of crypto algorithms
4 votes

Regarding AES: AES in a straightforward, single-block mode is generally written in a way that can be vulnerable to cache timing attacks, and potentially related attacks like Spectre. This is because ...

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Is all of encryption based on xor?
4 votes

You don't have to use XOR, but rather, it tends to be convenient. One of its convenient properties is that it is its own inverse. Also, XOR implements addition in $\mathbb F_{2^n}$, making XOR a key ...

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How do you communicate the hash function used with RSA signing?
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4 votes

Normally, yes, the hash algorithm in use is communicated beforehand. For example, sending an algorithm identifier during the TLS/SSL handshake process. However, depending upon the "padding scheme" ...

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Vertical bar and comma in hash function input
2 votes

I don't know anything about IEEE 802.11i, so I can't be sure about my answer, but hopefully this provides some insight. From the way in which the formula is written, $H$ is probably some sort of ...

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Does Poly1305 have weak keys like GCM/GHASH?
1 votes

After Daniel S's answer above, I wrote code to exhaustively search for all elements whose order $\le {2*23*32985101}$--the weak keys--while matching Poly1305's $r$ mask. Here is the complete list of ...

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What information is needed to be stored for RSA private key for decryption
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1 votes

In RSA, there are various numbers that are (kind of) equivalent to the private key, but aren't the private key per se. These are numbers that if you know them, you can calculate the rest of the ...

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Ways to make white-box cryptography AES implementation more difficult to be broken
1 votes

I just wanted to add a reverse engineering perspective on this sort of thing, since I've broken some such systems before. Attackers often don't care about unraveling the math to determine the ...

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Efficient way of generating a random number of N (less than 64) bits with exactly M bits equal to one
1 votes

The problem for choosing $k$ bits from $64$ ultimately comes down to computing a uniformly random integer $r$ with $0 \leq r < \frac{64!}{k!(64-k)!}$ then decoding it to determine which bits. The $...

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AES S-Box: How is value for 01 mapped to 7c?
1 votes

$00000001$ is its own inverse in the Rijndael field, because polynomial multiplication by itself gets $00000001$ and is unchanged by the modulo operation. This will always be true in any ring, as ...

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One Step Decryption For Multiple Chained Encryptions
1 votes

By definition, there exists such a function. Your function $g(z)$ could be simply a table of all the possible values of $f(f(f(x, y), y), y)$ mapped back to one of the possible values of $x$. I ...

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Why does a fixed key not make MACs like CBC-MAC or GMAC into secure hash functions?
1 votes

GMAC, for example, is trivially broken if used as an unkeyed hash algorithm. GMAC is effectively a series of operations on blocks where you take the previous state, XOR it with the next block, then ...

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Sender and receiver having different moduli conflicts with encryption and signing in RSA
1 votes

With public-key algorithms, you don't do encryption and signing of the message using the public-key algorithms themselves. Instead, you use traditional symmetric algorithms for encryption and hash ...

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RSA: Recover e given factorization of N and plaintext/ciphertext pair
0 votes

If you really mean the public exponent, most likely, the exponent $e$ is small; in fact, it's usually one of $\{ 3, 17, 65537 \}$. Just calculate $m^e \mod N$ and check whether it equals $c$. If you'...

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Leading 00 in RSA public/private key file
0 votes

I have seen this before in Java. Java's BigInteger class requires and generates binary data as signed little-endian. If the high bit of the first byte is set, the whole number is interpreted as ...

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Possible to guess RSA public key $e$ using $n$ and $\phi$
0 votes

For the problem of determining the base ($m$), the problem is that you don't have enough information. For any valid value of $e$, there is a matching value $m$ that encrypts to the same $c$; ...

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