23 questions linked to/from Definition of textbook RSA
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### Input limitations on the RC6 cipher

RSA has limitation in input size for encryption and decryption. Can RC6 be used for encryption and decryption of files larger than 5 MB? Is there any limitation for input size? Is RC6 safe for using ...
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### RSA How to select a value K such that $e d = 1 + k \varphi(N)$ holds

I am learning RSA cryptography. The part I am stuck on is understanding how k and the public exponent $e$ is selected. Given the formulas; Decrypting: $c^d \bmod N = (m^e)^d \bmod N$ Which is equal ...
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### RSA encryption/decryption process is not working correctly

I'm trying to apply the RSA cryptosystem to encrypt a byte M=72, using predefined modulus n, public key exponent ...
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### Help with RSA step

There's one thing in RSA that haunts me. In books there's just a statement, that $$ed \equiv 1 \bmod \varphi(n)$$ is taken from Euler's function somehow. And than we use it to get m^{ed} \equiv ...
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### Why plain RSA encryption does not achieve CPA-security?

Why plain RSA encryption does not achieve CPA-security?
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### I think I'm trying to find the C in an RSA cipher to find the key for an aes_128_ecb cipher, can anyone tell me if I'm on the right track?

And if I am on the right track, how do I reach the solution from here? I'm doing a CS game and I've hit a wall (I'm a rank beginner when it comes to encryption) on the encryption portion. I've been ...
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### Does order matter for RSA when used multiple times?

I actually have no idea how RSA works, but I currently (think that I) know Public and private keys are mathematically doing their opposites Therefore, the order in which they are applied doesn't ...
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### How does the math part of RSA work? [duplicate]

I understand the theoretical part of RSA (the concept of public and private keys), but I don't understand the mathematical part. Can anyone please explain it to me in simple terms? Thanks.
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### How secure is 'Plain Old RSA' [duplicate]

Let's say I use RSA encryption, it's 2048 bits and I use a simple character padding scheme, every character is turned into a 3 digit number and strung together, then encrypted. Saying that no message ...
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### Are there comprehensive alternatives to RSA?

If we wished to, is there a comprehensive alternative to RSA? I say comprehensive as I wonder if there is one which does both encryption and digital signature like RSA? If not, simply what ...
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### RSA problem - how to find $d$ [duplicate]

For example, let $p = 3$ and $q= 11$, choose $e = 3$. What computation I have to apply in order to find the corresponding $d$? I know it's 7, but I want to know the exact process to be applied to find ...
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### special public keys and modulo n

I just picked up cryptography and have some questions on RSA cryptosystem: Say there are two public keys (n, e1), (n, e2), e1 is coprime to e2. They share the same n. Is it possible to find the ...
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### OpenSSL RSA same plaintext but different ciphertext

how OpenSSL RSA work ? I generate public (n,e) and private key (n,d) then I encypted a file by : ...
I remember $e=3$ is a bad choice for textbook RSA. But I can't really recall why. What happens if I choose $e=3$? Can I retrieve the message by simply calculating $\sqrt{c}$? Why can't I do that ...