# All Questions

19,183 questions
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### how to compute Bit Independence criterion of SBOX?

I want to compute BIC's of my Sboxes, I found out some theses for that but I could not understand how to do it. Can someone help me?
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### curve25519 by openSSL

How can i generate ec curve25519 keys using openSSL? When I run openssl ecparam -name curve25519 -genkey -noout -out private.ec.key I have this message ...
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### NIZK proof for Order-preserving encryption

Suppose a cipher c=Enc(K,m), where Enc() is the order-preserving encryption scheme. Can NIZK be used to generate a proof to prove that c is indeed encrypted by m? The Schnorr NIZK is based on discrete ...
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### Build a PEM file by having ec public key coordinates

I have the coordinates (x,y) of eliptic curve point that is my public key. How can i build the PEM ( or DER ) file for my public key? I don't care about language (java, python, javascript, ...), ...
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### Static Diffie-Hellman in TLS

Static Diffie-Hellman (cipher suites with DH in their name but neither DHE or DH_anon - ...
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### Zero knowledge proof with sum

All zero-knowledge protocols I have read so far for discrete log works like this: 1) Prover generate a random number $r$, creates a commitment $t=g^r$ and sends $t$ to the verifier. 2) Verifier ...
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### How is an Encrypted iTunes Backup's Manifest.db encrypted?

When you do an Encrypted iTunes Backup, it encrypts the data but it also encrypts the Manifest.db file as well, which contains the information about the rest of the iTunes Backup. How is the ...
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### Security of HOTP over an unencrypted channel for controling an actuator

I have a simple on/off actuator that I want to control remotely. I want to use available hardware: a pair of microcontrollers connected to a pair of wireless transceiver modules. Can HOTP algorithm ...
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### Do AEAD algorithms and encrypt-then-MAC mitigate external decryption oracles?

I'm curious about a possible attack scenario that I'm not sure exists. If it is possible, I'd like to know if and how AEAD algorithms and encrypt-then-MAC implementations protect against it. The ...
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### Why in Efs file system (windows OS) is not possible to encrypt directly a compressed file? [migrated]

EFS File system doesn't permit to encrypt directly a compressed file. The opposite process is clear because is impossible practically but this one i can't understand
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### Group Rings on Cryptography

Let $R[G]$ or $RG$ be the group ring where $R=F_q$ and $G$ is any group. Let $Dim(V)=\vert G \vert$. It's clear that $V$ has $\vert R \vert^{\vert G \vert}$ distinct $\vert G \vert$-tuples. This ...
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### In which public key encryption algorithms are the private and public key not reversible?

The RSA public key encryption system has the characteristic that the public key and the private key can be reversed. That is, information encrypted with the public key can be decrypted with the ...
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### MPC and Secret Sharing in not Fully-Connected Network

I have an interest in applications of MPC and Secret Sharing. My point of view is from fields of distributed computing and Game Theory. I want to generalize some results to arbitrary network ...
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### Encryption/Decryption on multiple users using RSA?

Supposing I have Alice that is the RA, Bob (who is a user) and Kate (who is also a user). For now I use RSA. Alice sends a message to Bob. Alice also sends a message to Kate. Bob and Kate exchange ...
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### Signal Protocol - One Time Pre Keys (OTPK)

In Signal Protocol one time pre keys are a key only used once by Alice and taken from Bob, they provide forward secrecy (If the identity private key and signed private pre key which were used to ...
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### Modifying Elliptic Curve Parameters

For context, I was watching this bit of the video: which goes over this source code. The piece is about elliptic curve cryptography and how it works. I want to use some of this knowledge to make my ...
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### How can the Enigma's plugboard settings be found with partially known plaintext?

I don't quite understand the procedure described on wikipedia, is there a generalized procedure you can follow to rule out a pairing on the plugboard? For example, let's say the cipher text is ...
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### How does sha-2 with fewer rounds work?

The wikipedia page about sha-2 states: Currently, the best public attacks break preimage resistance for 52 out of 64 rounds of SHA-256 or 57 out of 80 rounds of SHA-512 How exactly is the sha-256 ...