# All Questions

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### Mitigating weaknesses in RC4 [duplicate]

I've been researching RC4 and implementing it, and I was wondering, from the perspective of a cryptographer (a real one, not a fake one like me), what could be added to the RC4 algorithm to improve on ...
28 views

### Choosing between RLWE-KEX methods.

Recently, I've been researching and implementing a bit of post-quantum cryptography, and I came across two RLWE-KEX algorithm for key exchange. The first one, which I implement in my software, is ...
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### Computational Randomized Encoding in the hybrid proof

A computational randomized encoding scheme $(\textrm{RE.Encode}, \textrm{RE.Decode})$ works as follows: $\textrm{RE.Encode}(1^\lambda, C, x, r)$: takes as input the security parameter $\lambda$ in ...
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### How does one practically calculate the non-linearity of a multi-output boolean function like the AES s-box?

I am working on multi-output boolean function i.e. a function that takes an $n$-bit input and gives an $m$-bit output for all possible inputs (i.e. $2^n$ inputs). To be more exact: I am trying to do ...
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### Help with a ctf im stuch on, base64 encryption [on hold]

So my friend and I were trying to do this ctf challenge here labyrenth .com and when we were trying to solve the first part of the "Threat" challenges we stumbled upon a challenge we have no idea how ...
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### SEAL Homomorphic multiplication

In SEAL homomorphic encryption library, there is an internal procedure to decompose a polynomial with large coefficients into a vector of polynomials with smaller coefficients. The procedure is ...
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### How to distribute system parameters in identity-based encryption

Identity-based encryption papers describe that system parameters are declared as public. However,in real scenario, how to distribute system parameters to users?
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### Time efficiency of Bitcoin Multi-signature Vs. threshold signature

I read this paper (Securing Bitcoin wallets via a new DSA/ECDSA threshold signature scheme) that illustrated that threshold signature is the best solution to avoid single point of failure but I think ...
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### Why are asymmetric keys represented as base 64? [on hold]

When one generates a public and private key with say a total of 4096 bits, why does the program output what I assume to be base 64 instead of base 10 or binary?
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### Designing Secure Multi-Party Computation Sub-Protocols Based on Homomorphic Encryption

When designing SMPC protocols using secret-sharing, it is a common approach to compose a protocol from several sub-protocols (each proven secure under the formal definition of security w.r.t. semi-...
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### How to choose key from string?

do you know any methods for choosing specific position in text for a key? Background: Lets suppose, that I want to encode message to friend: Text1 (not too long - max 1000 chars). I have made ...
5k views

### Can I remove newlines in a public key?

Can I remove new lines from the RSA public key file to get a one line string? So the question is if the key looks like this AAA BBB CCC or ...
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### Unique decentralized ID systems

We are all familiar with the standard decentralized ID system, the web of trust, e.g. for PGP keys. However, normal web of trust systems are unable to guarantee uniqueness — there's no practical limit ...
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### Are there any signatures based on matrix multiplication with noise?

Are there any signatures based on matrix multiplication with noise? Representing the message as a matrix and multiplying with some randomness coming from another matrix such that the signature itself ...
750 views

### Would it be better to split a file and then encrypt, or vice versa?

Assuming that you are paranoid before storing your file (distributed across a shared location), which will be the best case scenario: splitting the file first and then encrypting or encrypting first ...
493 views

### Timing attack on RSA as used by CryptoLocker?

So far I have researched timing attacks on RSA, We all know the ransomware named CryptoLocker uses RSA 2048 bit encryption. Now, is it possible to break the encryption using a timing attack. I have ...
408 views

### Toy encryption system that provides “hints”

I'm looking for a toy encryption system that has a specific property that when decrypting it with a key that is close enough to the key used in the encryption, it will produce some of the original ...
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### Using e-ID Number for Encryption and Digital Signing

I want to use e-ID number for performing Encryption/Decryption and Digital Signing - and in order to do so, I've opted a PGP-oriented approach which goes a bit like this. Generating PGP key-pair ...
473 views

### Compact digital signature for noisy data

The question asks for a signature scheme, with a public verification procedure, that is tolerant to minor alterations of the signed data during its transmission [possibly in analog form over some ...
1k views

### RSA digital signature vs authenticated cipher

I want to provide both confidentiality and integrity for data at rest (many large files stored on disk). I plan to encrypt the data using AES, which will cover the confidentiality requirement. So ...
131 views