-2
votes
0answers
33 views

Unlock my ZipCrypto deflate [closed]

Can anyone help me I have forgot my password for my file.. ZipCrypto deflate. I need a software to unlock the file. Please anyone assist me on this matter
-2
votes
0answers
37 views

suitable method for encryption and decryption [closed]

I want to encrypt and store important data in mysql so that no one else can access its original form and I want to decrypt those data whenever required. Which encryption scheme is suitable for this ...
-2
votes
1answer
43 views

What is contained in a RSA key file? [duplicate]

Consider a RSA key file like this: ...
-2
votes
1answer
97 views

simple encryption scheme turns out to be “somewhat homomorphic”

In the paper Fully Homomorphic Encryption over the Integers in the introduction: How do I calculate $r$ and $q$ of this equation in the picture? $r \approx 2^{\sqrt{\eta}}$ and $q \approx ...
-2
votes
1answer
58 views

How does the signature checking work in DKIM?

As far as I understand DKIM works like this: DKIM is not used to encrypt anything, the only purpose is to mark mails that are not really sent from the claimed domain as spam. the DKIM-enabled ...
-2
votes
0answers
111 views

Symmetric-Key Based authentication [closed]

So i've managed to answer all the other cryptography questions, but I have not come across this exam style question before, and need help.
-2
votes
1answer
148 views

Zero Knowledge Proof for Correctness of the product of additive ElGamal Ciphers [duplicate]

Suppose we use Additive ElGamal defined as follows: Let $(K,E,D)$ be a triple. The key-generator $K$ outputs the description of a finite multiplicative group $G$ of prime order $q$, with three ...
-2
votes
0answers
1k views

encryption and decryption time for RSA-crt in java? [duplicate]

I try compute execution time for encrypt and decrypt data has 1024 bit = 128 byte in RSA-crt algorithm. I need this results. But I believe this result wrong. because big diffrent between execution ...
-2
votes
1answer
276 views

Cryptography based upon neural networks [closed]

I would like learn about use neural networks in cryptography. Is there any research literature on this subject? What should I do to learn about the subject? I am taking short course in neural ...
-2
votes
0answers
565 views

Fiat-Shamir signature [closed]

I have a question about Fiat-Shamir signature: A hash function is h(w)=w mod 2011 and w1=2623, w2=3269, w3=1938. What is h=? and how to determine k.t bits?
-2
votes
0answers
384 views

Why is there a strong distinction between stream and block ciphers? [duplicate]

If I don't err, in the literature a stream cipher is one in which each plaintext bit is processed individually, commonly via xor-ing with one bit of a random or pseudo-random bit stream, while a block ...
-2
votes
1answer
76 views

Which Block cipher mode should I use? [closed]

Which of the Block cipher mode is MOST secure? I dont care about the performance just the most secure
-2
votes
1answer
69 views

What is Initialization vector (IV) [closed]

I am not the best cryptologer and therefore I have some questions so I learn more and get better. Heres the questions: What is Initialization vector (IV)? MUST I use it or not?
-2
votes
1answer
69 views

FEAL-4 Fk Function 4 Rounds

As I understood in FEAL-4 it needs 4 pair of round keys. Which means that we need to launch Fk function 4 times. My problem occurs starting the 2nd round. At the first round we have the original 64 ...
-2
votes
1answer
117 views

Is XORing a SHA256 better than truncating it? [duplicate]

Let say I want to truncate SHA256 to 128 bits. What would be the best way to minimize a probability of a collision and improve collision resistance? Taking the last 16 bytes Taking the first 16 ...
-3
votes
2answers
1k views

finding collision for truncated SHA1 hash output

Suppose we truncate only 40 bits of sha1 hash output.hence it is insecure.how can we find two message as input which gives first 40 bits of hash as same value i.e we have to find collision for first ...
-3
votes
1answer
146 views

ASCII Message in TV show? [closed]

So I was watching a popular series tonight (Person Of Interest) when suddenly during a frame change I noticed a very quick blue screen with writing. At the time I never thought anything of it as it ...
-3
votes
1answer
115 views

RSA public key security issue

The public key for RSA is $[e,n]$. Since $n = p * q$, are $p$ and $q$ already exposed because it takes no effort to figure out $p$ and $q$ from $n$?
-3
votes
1answer
116 views

Attacking multi block MAC constructions

For variable-length messages, there are three different ways to generate the tags. $Tag = MAC_k(\Sigma_i m_i)$. $t_i = MAC_k(m_i)$ and $Tag = (t_1, ..., t_l)$. $t_i = MAC_k(i||m_i)$ ...
-3
votes
1answer
145 views

can anyone give the java code to encrypt files using paillier [closed]

I want to implement encryption on personal files using paillier encryption. Is it possible to encrypt files using this encryption..
-3
votes
2answers
95 views

Selection of cryptographic functions for OAEP

I can't understand how the "cryptographic functions" are to be selected RSA + OAEP which are used in OAEP. How to choose these "cryptographic functions"(G and H)?
-3
votes
1answer
1k views

Is it possible to generate an RSA SHA1 signature only from a public key?

Is it possible to generate signature only from Public key. See example below where i have valid signature but what if I change hash ? Is then any way to do this? Public key(160 bytes): ...
-3
votes
1answer
133 views

Is encryption mainly using Diffie-Hellman Key Exchange?

I know how Diffie-Hellman Key Exchange works. Is this the main way of encrypting with PGP, ssh, ssl (https), DKIM, ...? I wonder if Diffie-Hellman is the clue to understand how encryption with ...
-3
votes
1answer
198 views

Currently i am doing decryption for RSA encoding and i face some problem with it [closed]

I am very new to cryptography so I don’t know much about it. I have been given a very large $N$ value and $E$ value to decrypt a ciphertext which was created using a AES 128 key and a IV by using RSA ...
-3
votes
1answer
86 views

cryptography permutation [closed]

Let $\pi$ be a permutation of the integers $0$ through $2^n-1$ (the integers that can be represented in $n$ bits). For example, $\pi$ could be used as a substitution cipher in which each plaintext ...
-3
votes
1answer
341 views

List of available symmetric & assymetric ciphers [closed]

I was looking all over the Internet list of ALL existing symmetric and asymmetric ciphers. I know that there's, for example, AES, DES, Blowfish, DSA. But how about more? Where to find such list?
-3
votes
0answers
25 views

can you solve exercise 1.20 Stinson [on hold]

Can you help me for solve exercise 1.20 of "Stinson" text book? Excuse me.I have no time to write the exercise.
-3
votes
0answers
73 views

Is there any specific name for Shamir's attack? [closed]

Is there any specific name for Shamir's attack? Because, I didn't find any attack named "Shamir's Attack" in Wikipedia. Shamir seemed to have published one article which showed that he can attack MH ...
-3
votes
0answers
306 views

RSA encrypted in logarithm. Is it right or wrong? [closed]

Factorization and primality test of Lepore-Santo in 4*log [(Y-X)/6]+1 I will show you the basic example, that i sto say the factorization of two prime numbers because reterating this process we can ...
-3
votes
1answer
92 views

Is there an encryption that is only reversible with a key?

I'm thinking about man-in-the-middle attacks during a website login, and started wondering about reversible encryption. What I'm imagining is an encryption that takes input ...
-4
votes
3answers
417 views

IV's from Crypto++ AutoSeededRNG always ends the same: Problem with the PRNG? [closed]

I am using a AutoSeededRNG from Crypto++ to generate IVs for use in CBC encryption. I am encoding the IVs using Base64 for future use (decryption). I notice that ...
-4
votes
2answers
209 views

Any techniques for evading frequency based crypt analysis without encrypting?

Are there any general techniques for evading frequency based crypt analysis without using any encryption techniques?
-4
votes
1answer
197 views

How does Diffie-Hellman key exchange work? [closed]

I've been learning about cryptography lately and I'm failing to understand how Diffie-Hellman key exchange works. Can someone please demonstrate using mathematical notation (and if possible, ...
-4
votes
2answers
164 views

pairing-based schemes

some authors claimed that computational performance of a pairing-fee scheme (based on scalar multiplication over an elliptic curve group) is about 1000% more efficient than a pairing based one I would ...
-4
votes
1answer
186 views

Storing the activation status of a product and expire details Android [closed]

In my Android application, it's required to store the activation status of the software and keep track of the activation expire date. What is the best way to store this information? Is it safe to ...
-4
votes
1answer
105 views

What is the best (thoroughly covering) textbook for application of LFSRs in cryptography? [closed]

What is the best (thoroughly covering) textbook for application of LFSRs in cryptography? (Beside Cipher Systems by Beker & Piper)
-4
votes
2answers
3k views

Algorithm/Technique for Steganography [closed]

What is the most used Algorithm/Technique in Steganography? I made some research about the algorithm/technique and I think Least Significat Bit(LSB) is the most used algorithm, is there any more ...
-4
votes
1answer
170 views

Can someone tell if my Hand Cipher is secure? [closed]

In easy steps, this is how it works: Convert txt to numbers. mod 1-26. Generate random numbers (by my other cipher) equal to plain txt. Write random numbers under txt numbers. Like this: ...
-4
votes
1answer
716 views

128-bit Pseudorandom number Generator

Is there any 128-bit pseudorandom number generator available? I tried the Blum Blum Shub Generator, but I can't produce a 128-bit pseudo-random number. Maybe before I produce a 128-bit pseudorandom ...
-4
votes
1answer
35 views

how to integrate 2-3 algorithms to encrypt large data fastly and securely insted using AES? [closed]

I am thinking to build an encryption algorithm which take less time when encrypt large data such as video,mp3 and which has security credential.
-4
votes
2answers
63 views

Why would cryptography fall apart if there were a finite number of primes? [closed]

I vaguely know that prime numbers are very important in cryptography, but I assume for most encryption methods, they tend to stay rather 'small'. Are we really using massive prime numbers for ...
-4
votes
1answer
101 views

Alternative encryption algorithm

I need a alternative encryption alcorithm to AES. It shouldn't be AES, Twofish or Serpent and it must be very strong. I dont care about the performance.
-4
votes
1answer
37 views

cipher inside and image [closed]

I have a short cipher of (33) characters , which is only ascii characters. From this information. Is it possible to guess what kind of encryption was that?
-4
votes
0answers
31 views

Winmain Error on Cygwin [closed]

I am running some C code, i have not made this code but from the comments the code seems to work. For the code to work i have saved a header file than compiled the code. I keep getting this error ...
-4
votes
0answers
46 views

Why is plain ElGamal not secure?

Why is plain ElGamal not secure? What is the proof behind it?
-5
votes
4answers
145 views

Solution with high decryption cost and low encryption cost

I am looking for any cryptographic solution that will meet those requirements : Only known method to get the encrypted string need to be brute force. Decrypting on modern computer not more than ...
-5
votes
1answer
96 views

RSA Key and RSA Security

Is there any relationship between the RSA keypair standard and RSA security? Keypair: http://en.wikipedia.org/wiki/RSA_(cryptosystem) Security: http://en.wikipedia.org/wiki/RSA_Security If not, ...
-5
votes
1answer
264 views

Multi layer encryption with ECB mode [closed]

if i use the 2 of the same key with 2 of the same algoritm when encrypting in ECB like when i have 2 blocks of the same color and i encrypt the 2 blocks with the same color the cipher text should not ...
-5
votes
1answer
265 views

Which encryption method used to crypt this text? [closed]

This is encrypted text: http://pastebin.com/bsHQ3Xvs It starts with <~ and ends with ~> What's the name of this encryption method?
-5
votes
1answer
40 views

Creating a new cipher! [closed]

http://flashbackcipher.blogspot.ae/2015/03/introducing-flashback.html Hey guys the above is the blog for a new cipher, if you guys can take a look and suggest problems.. it would be of great help!! ...

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