-1
votes
1answer
157 views

Obtaining a key that's using ice algorithm

I have a text file that has been processed by the SNOW steganography tool that uses ICE encryption. However, I do not know the key that would enable me to decrypt and retrieve the message hidden. ...
-1
votes
1answer
66 views

construct an election protocol for the following election problem..? [closed]

I am something new to election protocols and I am trying to construct an election protocol for the following problem: Let $A= \lbrace a_{1} , . . . , a_{n} \rbrace $ and $B = \lbrace b_{1} , . . . , ...
-1
votes
1answer
442 views

File Encryption/Decryption in ECB mode [duplicate]

Possible Duplicate: Removing Padded Value in Decrypted Message I tried to encrypt and decrypt a file in ECB mode using AES Algorithm but I encountered one problem during decryption, I don't ...
-1
votes
0answers
19 views

Recommendation for encryption of db fields [on hold]

Looking for java library who is capable to encrypt db fields of postgres 9.x database
-1
votes
0answers
64 views

Working a problem that uses RSA encryption:

To overcome weaknesses of the textbook version of RSA encryption, commonly some form of padding is applied.Consider the following suggestion for an asymmetric RSA-based encryption scheme: Key ...
-1
votes
0answers
36 views

Using the chinese remainder theorem as a part of the proof, show that 2^700 = 1 mod 3625 [closed]

Using the chinese remainder theorem as a part of the proof, show that 2^700 = 1 mod 3625 Using the chinese remainder theorem as a part of the proof, show that 2^700 = 1 mod 3625
-1
votes
0answers
33 views

Are RSA keys stronger than McEliece keys?

What the title asks. I'm currently of the opinion that differences in key size don't make either stronger or weaker than the other in this case.
-1
votes
0answers
30 views

Calculating hash of hash in C [closed]

I've been working with Openssl libcrypto for a long time and I'm quite familiar with it but now I've got a problem I cannot solve in my own, so I need your help. I'm creating a hash of a short string ...
-1
votes
0answers
31 views

The RSA algorithm imposes size restrictions on the object being encrypted [duplicate]

The RSA algorithm imposes size restrictions on the object being encrypted. RSA encryption uses the PKCS#1 standard with PKCS#1 block type 2 padding. The PKCS RSA encryption padding scheme needs 11 ...
-1
votes
0answers
32 views

Worked example of McEliece Cryptosystem

I am trying to learn about the McEliece cryptosystem, unlike other more common systems, like RSA or El Gamal, educational literature such as the Handbook of applied cryptography doesn't contain worked ...
-1
votes
1answer
37 views

Generating cyclic group for Ciphertext-Policy Attribute-Based Encryption [closed]

I am doing Project under the topic CP-ABE.I need to generate a symmetric bilinear group Go of prime order p and with generator g...Then how to choose random elements from Zp....kindly anyone help ...
-1
votes
0answers
51 views

Chosen-prefix collision attack on 24 bit truncated sha-256

I need to answer this question for an exercise: I have a file on which a sha-256 hash is calculated, but only the first 24 bits of the hash are considered. I want to find another file which results ...
-1
votes
0answers
39 views

Methods for “chained authentication”

I am currently looking at different methods which can be used to perform what I would call "chained authentication". By chained authentication I mean authentication between two systems that cannot be ...
-1
votes
1answer
62 views

Montgomery and Galois fields

I'm a little bit confused about the design of a RSA module in VHDL. My question isn't directly related to hardware design. I've read a lot of publications and I bought also a book. In one publications ...
-1
votes
2answers
70 views

Is there a client-side program to cryptography a HTML page and decode if correct password is writen? [closed]

I want to know if there is an easy way to do this: create a complete HTML page cryptography the text content (image is not important) ask user some password check the password with a cryptographed ...
-1
votes
1answer
56 views

Problem with implementing DES in python

i'm implementing DES in python and i've stumbled upon a problem i can't really find the problem, after debugging it i narrowed it down to this function, can anyone tell me if i'm implementing the DES ...
-1
votes
1answer
66 views

How are calculated numbers in AES S-box? [duplicate]

My question is how to calculate the 0x02 value of AES S-Box? I followed this explanation, but my answer is not correct. 0x02 is ...
-1
votes
1answer
51 views

Modular Reduction of polynomials in GF(2^m)

Hello I am having trouble understanding the algorithm implementation in hardware of the reduction process over galois fields of F(2^163) In the following process it ...
-1
votes
1answer
51 views

CoAP authentication using DTLS

what is the meaning of this notation ?? AES{Yi, (Yi XOR Ki | nonce1)} https://tools.ietf.org/html/draft-bhattacharyya-core-coap-lite-auth-00
-1
votes
1answer
98 views

Cracking plain RSA by factoring the modulus n

This is the setup: I have both public and private keys of one "instance" of RSA. And I have only the public key of another RSA cryptosystem, but this system has the same modulus as the first one. I ...
-1
votes
1answer
206 views

Collision resistant hash functions

Let (Gen1,H1) and (Gen2,H2) be two hash functions. Define (Gen,H) so that Gen runs Gen1 and Gen2 to obtain keys s1 and s2, respectively. Then define Hs1,s2(x)=Hs1(x)||Hs2(x). a) Prove that if at ...
-1
votes
1answer
86 views

Isn't Groth-Sahai proof system applicable beyond Bilinear groups?

Classical paper by Groth-Sahai on NIZK proof system is titled as "Efficient Non-interactive Proof Systems for Bilinear Groups". To my understanding, only (Pairing Product Equation) PPE are defined ...
-1
votes
1answer
82 views

What are the advantages of Certificate Authority and Key Distribution Center over each other?

I want know difference among them. What are advantages/disadvantage of one on other?
-1
votes
1answer
83 views

Bouncy Castle and Salsa 20

I want to use Salsa 20 in Java, so I downloaded Bouncy Castle, and... it makes no sense to me. I've got it working, but most of my choices were essentially random. But I can't see there anything ...
-1
votes
0answers
81 views

Calculating periodicity of a pseudo random number generator (Middle-square method) [closed]

Below is a Python code that calculates the periodicity of the middle-square method for a given 4 digit-numbers: ...
-1
votes
1answer
149 views

What does it mean that a protocol realizes “strong mutual authentication”?

What does it mean that a protocol realizes "strong mutual authentication"? And What does it mean that a protocol realizes "weak mutual authentication"? Can you define them formally ? I have found a ...
-1
votes
1answer
109 views

How is a Yubikey static password derived from the AES key?

When I configure a Yubikey slot as static, it's not documented or obvious how the static password yielded by a press relates to the AES key I set. For example: ...
-1
votes
1answer
91 views

How to benchmark custom crypto with OpenSSL benchmark suite? [closed]

OpenSSL benchmark suite currently tests the speed of algorithms supported by the library like md5 sha1 sha256 sha512. What if we have a custom crypto algorithm "abc" . How do we benchmark its ...
-1
votes
1answer
117 views

Attacking both authenticity and secrecy in authenticated encryption modes

looks like NIST only approved GCM mode for authenticated encryption and other modes don't have any approval or a good implementation available. Is that possible a weakness in $GHASH$ compromise ...
-1
votes
1answer
293 views

Guessing encryption algorithm based on key and ciphertext

Is it possible to tell which encryption algorithm was used, assuming I have a key and a encrypted text? To not complicate the situation let assume we are speaking about symmetric algorithms only. ...
-1
votes
0answers
159 views

Approaches to decoding data of an unknown type [closed]

This is a high level question. One area of computer science that I'm working on getting better at is encoding and decoding data. My background is that of a self-taught web engineer who is trying to ...
-1
votes
1answer
74 views

HMAC-Ripemd-160 in TrueCrypt

I'm wondering if it is still secure. I know TrueCrypt closed its doors but I continue using it because the cryptoaudit didn't find any huge bugs or security issues in TrueCrypt. But I have a bad ...
-1
votes
2answers
144 views

Encryption algorithm designed to be easy to decrypt by machine but impractical to decrypt by hand

I am looking for - or considering the design of a new - encryption algorithm that does not use variable keys, such that it is easy for a computer to encrypt and decrypt any message regardless of its ...
-1
votes
1answer
102 views

Can Diffie-Hellman generate values in a specified range?

Is there any way to generate values only between $0$ and $255$ with the Diffie-Hellman method? I need to create keys for communication algorithms with $32$ and $16$ numbers between that range. The ...
-1
votes
1answer
53 views

Diffie-Hellman on infinite groups

The most common groups to be used as examples for the DH protocol are modular multiplication and elliptic curves. But I've realised that the groups doesn't need to be finite, a suitable infinite group ...
-1
votes
1answer
157 views

How does hash function in Elgamal signature scheme prevent existential forgery attack?

I have heard that hashing the message M prevents an existential forgery attack. I was wondering how.
-2
votes
5answers
208 views

Is symmetric encryption no longer necessary?

Here is it: Symmetric encryption is no longer necessary, because all security services can be implemented with public-key cryptography. Moreover, in public key cryptography the operations for ...
-2
votes
3answers
2k views

How secure is the Vigenère cipher in file encryption if you encrypt the password first?

I created a basic file encryption method, that seems pretty secure to me (based on an answer below, it seems to be an implementation of the Vigenère cipher) , but one of my colleagues claims that it ...
-2
votes
3answers
1k views

How can I find the prime numbers used in RSA?

I got this question in a local hacking event, but I couldn't solve it. Problem Statement ---- Continuing their snooping habit, NSA kept bugging Alice's communication. Resorting to the age old ...
-2
votes
4answers
280 views

Do Brute-Force Attacks and Cryptanalysis refute Kerckhoffs's principle? [closed]

According to Kerckhoffs's principle "A cryptosystem should be secure even if everything about the system, except the key, is public knowledge." Now I want to throw in a provoking formula of mine which ...
-2
votes
2answers
207 views

Is (2^333)-1 a prime number? [closed]

How can I see if $2^{333}-1 $ is a prime number? Does this have to do with Mersenne prime numbers ($2^n-1$) ?? Thank you!
-2
votes
1answer
88 views

How many bits of entropy would I get from 300 coin tosses? [closed]

Bonus question, what is the formula to calculate this?
-2
votes
1answer
58 views

moduli in SSL certificates [closed]

this is normally seen in a typical SSL certificate. For the modulus, I know that it is represented in hexadecimal form, but why is there a semicolon (:) after every group of 2 digits? ...
-2
votes
2answers
301 views

How do I choose the best 3*3 s-boxes?

I've read about 20 papers about the criteria for choosing best $n \times n$ s-boxes. Now, I've got two problems: How to generate $2^{24}$ s-boxes, and how to test them considering the criteria. ...
-2
votes
1answer
54 views

How to write the encrypted message after using RSA

I have created a RSA encryption/decryption program but how do i write out the results after doing a encryption? Right now I have it so that it will just print out the decimal value of one character ...
-2
votes
2answers
246 views

How to decrypt 3DES in ECB mode (using a wordlist)? [closed]

I have some encrypted texts (encrypted with 3DES in ECB mode without salt). My question: How can I decrypt them using a wordlist? (or without one) Example: Encrypted text: ...
-2
votes
2answers
115 views

How to best mix two arbitrary/random n-bit words? [closed]

Given two arbitrary/random $n$-bit words, how could one best mix them to get one $n$-bit word for general crypto usages? I suppose that one should have an adequate measure of goodness of the mix ...
-2
votes
2answers
101 views

What is the difference between homomorphic encryption and homomorphic signature? [closed]

I want to apply homomorphic signature instead of homomorphic encryption in Provable data possession. So I want to know about homomorphic signature and homomorphic encryption.
-2
votes
1answer
373 views

Is my one time pad cipher secure?

This is a program that I made for encrypting text files. It uses a one time pad cipher to encrypt the files, but I do not know if there is any holes in my program that could be a vulnerability. Is my ...
-2
votes
2answers
367 views

How weak/strong is this hand cipher? (updated) [closed]

In simple steps here the system: first write text. hand cipher then divide into groups of three letters: han dci phe r then choose a key consisting of three letters, for example ...

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