Latest Crypto related questions

I have basic knowledge about how encryption algorithms work such as RSA, AES and so on. I have an XML response encrypted with both AES and RSA. I tried using OpenSSL to decrypt with several steps but am pretty sure am missing out or not getting the terminology right.

I did follow this step carefully https://security.stackexchange.com/questions/34589/how-to-you-manually-decrypt-a-soap-message-using-open ...

Maybe this sounds like a stupid question. I'm sorry for that.

I just wanted to know is it possible to encrypt a bitmap image file like *.BMP, and generate the ciphertext which is an obscure bitmap image where each pixel is random (The image maybe would looks like an analog TV without an antenna)?

There are a few steps in the public-key generation of GeMSS that I am trying to understand. The first is the below equations (1).

What does "$\theta_i$ forms a basis for $\mathbb{F}_{2^n}$ over $\mathbb{F}_2$" mean? I know what a basis is in linear algebra, but more details are needed so I can understand.
How do we interpret the map $\phi$?

1. $(\theta_1,\ldots,\theta_n)\in(\mathbb{F}_{2^n})^n$ form a  ...

I understand the premise of weak keys in DES and cryptography. From searching online, I understand that keys that are comprised of all zeroes / all ones / alternating ones and zeroes / alternating zeroes and ones are considered weak and should not be used. If I was to use the following key: 0110 0110 0001 0001, would this be considered weak; and if so, how come?

I'm having a problem with an encryption scheme.

There are two entities, $A$ and $B$. $A$ give a simple message $m \in [0,1]$ to $B$. $B$ should generate an encrypted message of $m$: $e=Enc_{pk}(m)$ such that $A$ can verify if $B$ has correctly encrypted a message generated from $A$ without tampering it. But, at the same time, $e$ should not reveal any information that can be used from $A$ to demons ...

I am looking for a simple encryption of the text messages and in order to save some bandwidth, storage etc, I was looking to encrypt them into the same length strings. Something similar to how youtube is doing for their video ids. Having billions of videos in their database, they manage to encode them with only couple of letters and digits.

Is there any encryption which can output the same length ...

Let $K$ be a number field of degree $n$ and $\Lambda^q_h=\{(f,g)\in\mathcal{O}_K\text{ : }fh-g = 0\bmod q\mathcal{O}_K\}$, where $h$ is an NTRU public key. Then $\{(1,h),(0,q)\}$ generates a lattice. I've found it stated in the literature that $Vol(\Lambda^q_h) = Vol(\mathcal{O}_K)^2q^n$ (e.g. here), but how does the proof of this statement run? Or where can I find a proof?

I've been learning about the elliptic curves and how they work, and their usage in cryptography, and I'm trying to figure out how to use them using Go.

1. Where is the 'a' parameter from my ECC equation y^2 = x^3 + a*x + b, in this CurveParams structure? https://golang.org/pkg/crypto/elliptic/#CurveParams To verify I am understanding well please correct me if I am wrong:

• 'P' parameter represents the order ...

community !

I'm looking for the proof of theoritical security of Shamir's secret sharing. I found some articles saying that it's assimilable to the halting problem, which implies that there is no general algorithm to solve it for all possible program-input pairs. But, I don't understand why it stands for SSS encryption.. Why we say that we can only calculate all possible solutions for a threeshol ...

I am a member of a sports association and I am developping a simple JavaFX application for managing member's license.

This application will be used on a notebook without any connection, it has to be offline an protected by a user/password. It will run on a shared Windows account.

The application must be the simpliest possible to install and use (average user age around 60-70 years old) so for storin ...

Merkle trees can be used for vector commitment scheme. In particular given two sequences S, S' with the same elements in the same order the merkle root for S will be the same as the one for S'. What if I need to append to S and S' the same elements over time but they may differ in ordering? Is there any specific commitment scheme best suited for this scenario?

I'm trying to encrypt and store strings in PHP as per example #1 on the PHP openssl_encrypt documentation.

<?php
//$key should have been previously generated in a cryptographically safe way, like openssl_random_pseudo_bytes
$plaintext = "message to be encrypted";
$cipher = "aes-128-gcm";
if (in_array($cipher, openssl_get_cipher_methods()))
{
    $ivlen = openssl_cipher_iv_length($cipher);
    

As it is depicted above, the Feistel Network uses random function fi which is not required to be invertible. However, if fi is not invertible, how can fi(Li) == fi(Ri-1)? Furthermore, why Feistel Network is invertible?

$\textbf{Continuous LWE}$ : $(\overrightarrow{a}, b)\in \mathbb{Z}_q^n\times \mathbb{T}$, where $\mathbb{T}=\mathbb{R}/\mathbb{Z}$, $b = \langle \overrightarrow{a},\overrightarrow{s}\rangle/q + e\mod 1$, where the error $e$ is sampled from $\Psi_\alpha(x) := \sum_{k=-\infty}^{\infty}\frac{1}{\alpha}\cdot exp(-\pi(\frac{x-k}{\alpha})^2), x\in [0,1)$ over the torus $\mathbb{T}$. The density function