-3
votes
1answer
722 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
132 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
113 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
940 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
69 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
2answers
132 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 ...
-3
votes
1answer
53 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
128 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 ...
-3
votes
1answer
85 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)
-3
votes
1answer
226 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?
-3
votes
2answers
2k 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 ...
-3
votes
1answer
582 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 ...
-3
votes
1answer
121 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
76 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
285 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
49 views

how much will it cost me to encrpt apps and website? [on hold]

gentlemen,I have a question. am planning to make a website an two Apps for android and Iphone and I want to make its encryption very strong. I don't know how much it may cost me and how to do it. is ...
-3
votes
0answers
29 views

Ciphertext-only cyptanalytic attack agianst the affine cipher? [duplicate]

Can you think of a ciphertext-only cyptanalytic attack agianst the affine cipher? Please explain step by step how it would work if possible.
-3
votes
1answer
80 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
324 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
195 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
80 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
1answer
151 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
4answers
76 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 ...
-4
votes
1answer
236 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 ...
-4
votes
1answer
222 views

AES implementation in java that allows key of 320-bit length [closed]

I need an implementation of AES(Rijndael) in java that allows use of a 320-bit key. Please suggest a reliable implementation
-5
votes
4answers
273 views

Found a way to crack AES-128, what now?

I have just found a way to crack AES-128 in a reasonable time (1-2 days). How do I publish and prove this? I remember reading about lots of people who cracked DES and other ciphers but how did they ...
-5
votes
1answer
80 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
2k views

Decrypting encrypted files if i have the original files(Plain Text attack) [closed]

I have the following A Encrypted file and the same file in its original(not encrypted) form Now will it be possible to find the encryption/decryption key by comparing the the above two files are ...
-6
votes
2answers
236 views

Snowden Challenge II: Can we solve Snowden challenge quantumly? [closed]

Suppose that tomorrow is July 7, 2050 and Snowden is still stayed in Sheremetyevo airport. Further, let us suppose that quantum computation and quantum commincation are available to everyone, and ...
-6
votes
1answer
76 views

AES ENCRYPTION ALGORITHM [closed]

What is the amount of decrease in the probability of decrypting a data encrypted using an AES algorithm? (That is by introducing each round out of ten whole rounds, how the probability of decryption ...

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