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0 answers

Entropy - Gas Inside A Closed System Reaches Maximum Entropy

Filling a box with a certain amount of gas with a specific total energy and allowing the gas to reach a maximum entropy state, what happens next? Would the gas remain in a maximum entropy state ...

2 answers

Js Deferred/Promise/Future compared to functional languages like Scala

I'm mostly using programming languages like Scala and JavaScript. I'm trying to understand the similarities and differences in how async reactive programming is used in both languages. Can you help ...

1 answer

Words in Index of coincidence using vignere

I am trying to interpret the formula for index of coincidence from here I am not understanding fi , How i can calculate fi in this context ? Is this the appearance of single word like (a) in the ...

3 answers

Google Cloud Storage Bucket - Public Access

I am using Google Cloud storage for my Google App Engine Application (using Php).I want act as a Local Image directory and want to access in img tag. <img ...

2 answers

Securing communications in decentralized network of servers

Lets consider the following setup: One has a decentralized network of servers. A single root certificate has been distributed to all servers which has been positively checked as authentic and ...

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Add seperators to signature block in latex pandoc template

I have a letter latex template for pandoc. I want the author's names to be seperated by commas or newlines or whatever. How would I get pandoc to do something like the below? I want it in the ...

0 answers

AES with CFB Mode

I want to encode my Url-params with Base64 and crypt(AES with CFB Mode), but it will not working and I can't get the error. Can someone help me? Here is my code: private String ...

2 answers

Key space vs Cardinality of 1024-bit RSA

I have been trying to figure out the encryption key space, and cardinality of 1024-bit RSA. From my understanding, the key generated from 1024-bit will be primes greater than $2^{1023}$ but less than ...

4 answers

Encrypt a string to match length of original string

I need a simple c# algorithm that will take a string of x characters and 'encrypt' it to another string of also x characters. It doesn't have to be secure, but it shouldn't be possible to reconstruct ...

4 answers | 4 hours ago by Johan on Stack Overflow stackoverflow.com
1 answer

Continuous joint entropy with fully dependent variable

Consider a variable $X$ with a continuous uniform distribution in the interval $[a,b]$ and a variable $Y$ that is fully dependent on $X$, i.e., $p(Y=y\ |\ X=x) = \delta (x-y)$, where $\delta$ is a ...

6 answers

Mathematically, why was the Enigma machine so hard to crack?

Mathematically, why was the Enigma machine so hard to crack? In laymen terms, what was it exactly that made cracking the Enigma machine such a formidable task? Everything I have seen about the ...

2 answers

Jasypt and asymmetric encryption

I want to use the Jasypt library to decrypt properties in Spring through the EncryptablePropertyPlaceholderConfigurer class. I want to encrypt/decrypt these properties using the asymmetric ...

2 answers | 5 hours ago by bogumil on Stack Overflow stackoverflow.com
3 answers

When using RSA algorithm, is it a risk if plaintext and its ciphertext are identical? if yes why?

Is it a risk if RSA produce exactly same ciphertext for the given plaintext?

3 answers | 5 hours ago by tester on Stack Overflow stackoverflow.com
1 answer

“The Two Sheriffs” puzzle -2: threshold for security

I've already asked a question “The Two Sheriffs” puzzle with wrong assumption. Yoav Kallus in his amazing answer using Fano plane showed that the problem has a solution in the case of seven suspects. ...

5 answers

RC4 encryption java

Hi there I am trying to implement the RC4 algorithm in Java. I found this code as an example that help me to understand the idea: public class RC4 { private int[] S = new int[256]; private int[] ...

0 answers

Attribute-based encryption for cloud storage

I'm trying to understand attribute-based encryption schemes. Almost all articles describe that they are designed for cloud storage, but as I understand, almost all computing (encryption & ...

2 answers

Length of prime number used in Pedersen Commitment

I am writing a program using a Pedersen commitment scheme and all I'm missing is an appropriate length for my prime $p$. I have heard that a length of $2^{80}$ is ok, is that correct?

2 answers | 6 hours ago by Chili on Cryptography crypto.stackexchange.com
1 answer

Plaintext block chaining, bad idea why?

Ahead of the question, little warning. Question is not about what are the better options. Question is why it is bad idea? Ok, suppose we have plaintext $p$, which divided into blocks: ...

0 answers

Security of basic SHA256 MAC in an authenticate-then-encrypt scheme

I know the following construct is insecure if the MAC as defined below is appended to the encrypted message in an Encrypt then Authenticate (EtA) scheme. $k_1$: encryption key $k_2$: authentication ...

2 answers

Proof DES is injective - is this a valid argument

Without going too much into detail into the crpytography of the matter since not every mathematician is interested or knowledgable in the field, there is an encryption process called DES (data ...

2 answers

How can I check in latex whether a new chapter starts on current page?

I am using the everypage package. Using the \AddEverypageHook command I can repeat actions at the beginning of every page of a document. Now I want to do soemthing like this: \AddEverypageHook{ \if ...

0 answers

Example of BouncyCastle Elliptic Curve implementation in C#

Could show me/or direct me to model example of BouncyCastle Elliptic Curve implementation in C# over real numbers and over Fp please? I think model example with "Alice and Bob" communication, where ...

1 answer

How to generate keys for RSA in Java

I got this code to encrypt/decrypt some String via RSA. This project is used to understand the encryption and is build only for learning purposes. Until now I always used a fixed key to use my ...

2 answers

A Game of Phones

The Chaos Legion is an infamous criminal organization, responsible for every major disaster in history from the burning of the Library of Alexandria to the recent Sony hack. The Order of Seven is ...

1 answer

Migrating password encryption schemas

I am possibly taking over an app that literally just encrypts user passwords by doing md5( password ) They have ~2000 users to date. How can I migrate those passwords to a stronger encryption schema ...

0 answers

Encrypt RSA with a PUBLICKEYBLOB Windows Crypto API

I have a PEM RSA private key stored as a const char* in my code and can decrypt some data which is encrypted by my client software using the associated public key just fine. However, I need to ...

0 answers

Should we close a basic question asked and answered in more complex terms elsewhere?

This question (update: now closed as duplicate) asks a basic thing: why the security level of 2DES is 57-bit (implicitly: given a few plaintext/ciphertext pairs). An helpful (if not quite correct) ...

0 answers

java.security.InvalidAlgorithmParameterException in RC5 implementation

I would like to use RC5 encryption in my app with other word sizes and round numbers than default. I used this implementation as a provider but when I call it I get: ...

3 answers

Why can't torrent traffic be encrypted?

I am trying to avoid having this be closed for being too open or unclear what I'm asking, although it is a bit open, admittedly. The goal of this question is that I am just trying to better understand ...

0 answers

Android javax.io.IOException: last block incomplete in decryption

I am trying to make a encryption and decryption app but in decryption method I got javax.crypto.IllegalBlockSizeException: last block incomplete in decryption byte[] key = ("Sh").getBytes("UTF-8"); ...

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