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Comparison Affine Coordinates and Projective Coordinates Addition in Excel

Kurve : EC : y^2=x^3 + x + 1 Generator:(1,7) p=23 Result in Affine use excel: P=(1,7), Q=(7,11) => P+Q=(18,20) Result in Projective use exccel: P=(1:7:1), Q=(7:11:1) => P+Q=(15:2:9) U = U1 - U2 ...

2 answers | 27 secs ago by Alfred Saut on crypto.stackexchange.com

xor matrix multiplication for AES mix column stage

Hi I'm writing program for AES mix column stage. Here I have to multiply two matrices of (4,4)shape. The only difference is that while multiplying two matrices I have to take 'xor' instead of where I ...

What would Lincoln say?

I got asked this question on a job interview, I am not sure if this is a right place to ask but here it is: If Abraham Lincoln were to give an address today, what would he say about us? Hint: 63, ...

What is the meaning of Boltzmann definition of Entropy?

I would like to ask if someone knows the physical meaning of Boltzmann's definition of entropy. of course the formula is pretty straightforward $$S=K_b\ln(Ω)$$ but what in the heck is the natural ...

AES File Encryption/Decryption

Objective: To pick File with JFileChooser take that File pass it into encryption method, encrypt file get the encrypted file then finally upload the file to a server via. the upload method I have or ...

File Encryption and Decryption using AES

First of all I'm totally new on cryptography, but I need to develop a program to encrypt and decrypt files. I want to use AES for encryption and decryption. My first idea was read the entire file in ...

How to Remove Enumerated Markdown in Jupyter with PDF

Whenever I convert to a PDF in Jupyter, the markdown boxes have numbers. This is inconvenient for my problem sets because I will be on the second problem, but my 4th markdown box. Is there a setting ...

will breaking not used anymore RSA codes in the future affect privacy?

just read and watch some stuff on how RSA works. main idea seems to be if someone steals your communication he cannot decode it anyway. but let's say someone steals it and keeps it along with current ...

Looking to replace an encrypt message using a repetitive block cipher

I'm looking to change this code and planning to do a block cipher. For example, let us say the message I would like to encrypt is: “Here it is!” Let us say our “block” is three integer numbers: 1, 5, ...

Secure randomized data matching?

This might be a dumb question but I will go for it. Let's say we have a data set $D$ consisting of sensitive data, and we want to be able to match if a new piece of data $S$ already exists in $D$ ...

2 answers | 2 hours ago by gronnbeck on crypto.stackexchange.com

How do I solve this transposition cipher?

(88 characters): ANNHA MSUIM HDSHP CEVVA LEOVE PAERS ADYSC TNLIE LIIET PTSRO CNAFM GONCO NMAMO RLEIT MSNSY LFOOI SASEO RGA. -- My introductory cryptography instructor assigned this, I calculated the ...

async's future holds on to copies of arguments after async task completes

Consider the scope { std::shared_ptr<T> data = new T(); std::future f = std::async(std::launch::async, operation, data); keep_for_later(std::move(f)); } where keep_for_later() stores ...

How to fix error exception java: error decryptAES Could not initialize cipher?

I have a exception, could not initialize cipher, and i can't fix it This is code: public static String decryptAES(String dataEncrypt, String key) throws Exception { synchronized(decryptLock) { ...

1 answers | 5 hours ago by langiac on stackoverflow.com

openssl smime: aes vs rsa - which one encrypts?

When I want to encrypt large files, I have found the following command: openssl smime -encrypt -binary -aes-256-cbc \ -in large_file.img -out large_file.img.dat \ -outform DER \ public-rsa2048.pem ...

1 answers | 6 hours ago by lockdoc on stackoverflow.com

References for information theoretic statistical tools

Strange statistical concepts like spaces of probability distributions, "metrics" like Fisher information or relative entropy, and convergence with respect to these quantities are necessitated in my ...

MIFARE DESFire EV1 read and send

I have a payment card which I use everyday which uses MIFARE DESFire EV1. I constantly forget my card so I thought it would be an interesting idea to "load" my card into my android phone and scan my ...

How to convert AES to a PRNG in order to run NIST Statistical Test Suite?

I want to run statistical tests on my implementation of AES. How should I convert it into a PRNG? Is there a standard way to go about doing this? I could not find much information about this although ...

What is the difference between MAC and HMAC?

In reference to this question, what are the "stronger security properties" that HMAC provides over MAC. I got that MAC requires an IV whereas HMAC doesn't. I also understood that MAC may reveal ...

2 answers | 8 hours ago crypto.stackexchange.com

I have a form where password is being encrypted on the client side and sent as 'post' once login is clicked. However, I am unable to prevent the password input to stretch to random string at the time ...

GPG: pubring.gpg and secring.gpg are missing

I'm a newbie to GnuPG. I was following the instruction "Generating a Key Pair" here: http://central.sonatype.org/pages/working-with-pgp-signatures.html And finally I do not see neither pubring.gpg nor ...

Port Java AES/ECB/PKCS5 encryption to Python

Is there a way to port following function from java to python? My attempts failed. The output is always the same for one input. Any ideas? Java Source Code: import javax.crypto.BadPaddingException; ...

Why is my @SuppressWarnings(“unchecked”) ignored?

Why is Javac ignoring my @SuppressWarnings annotation in the code below? @Override @Transactional(readOnly = true, timeout = 10) public List<Item> findAllDue() { Query query = ...

How much of IPsec has to be implemented outside ip xfrm?

Having found strongS/WAN to be almost entirely neglectful of any RFC relating to multicast, I stumbled across ip xfrm state and policy commands that do encrypt and decrypt multicast messages via ESP. ...

java spring - override property value received from property file

I have a scenario, where i get encoded password value from property file. I have own implementation of decryption, so want to decrypt the password from my java class and then want to use that ...

Call Back database row which is encrypted to store in PHP variable and compare with user HTML input

within the PHP,HTML,SQL codes which i have been uploaded in this post,i try to get input from user and encrypt it,and store it in in a PASSWORD row,and when the user LOGIN,i will retrieve back the ...

x509 certificate key to asymmetric algorithm

Re-doing this question since I don't know if I was getting my point across correctly. I have a signedXML object Dim signedXml As New SignedXml(envelope) I need to set the SigningKey property of ...

Asymmetric Crypto on Android

I would like to ask if i can use Asymmetric Crypto (like RSA or ECC) on android mobile phones, how, and what are the best libraries i should use.

How to encrypt a file using a Public Key in C#?

I have a 2048 bits public key (asymmetric, RSA) of which I know the Modulus and Exponent and need to encrypt a string. Ideally, I want to encrypt a small string in c# and later on decrypt it with ...