# All Questions

1answer
58 views

### Does encryption of data/information take place in peer to peer networks like Gnutella, Bittorrent?

Do peer to peer networks like Gnutella, Bittorrent have any encryption system to secure the users privacy or encrypt the file/data being shared? Elaborate please.
1answer
58 views

### bruteforce on aes 256 cbc mode

i have a series of encrypted text , they encrypted by aes 256 bit cbc mode for every encrypted text there is an iv that i have them also and i know its algorithm is aes 256 bit cbc mode i can ...
1answer
28 views

### Some terms related to secret sharing: Optimality, What does it mean?

In any secret sharing scheme we have to develop step by step. After constructing such scheme we need to reduce share size. Why? e.g. Robust secret sharing scheme is modified Shamir secret sharing ...
1answer
1k views

### Password hashing security of argon2 versus bcrypt/PBKDF2?

I wonder if it can be approximated how much of a security margin the new argon2 hash, winner of the password hashing competition, can give over bcrypt or PBKDF2, for an attacker using large GPU ...
3answers
632 views

### Advantages/disadvantages of using symmetric encryption function as hash function?

Next to the traditional MD5 and SHA-1, other hashing algorithms exist based on symmetric encryption algorithms. An example is the Matyas–Meyer–Oseas construction. What are the advantages/...
1answer
125 views

### ElGamal Signatures

I know various applications of RSA signatures. I wonder, is there any real-world applications of ElGamal signatures and encryption?
0answers
38 views

### Is the ring learning with errors problem still hard if the errors are drawn from some subspace?

Let $R=\mathbb{Z}_p[x]/x^n+1$ be the ring used in normal RLWE, which is linear space over $\mathbb{Z}_p$ with dimension of $n$, let $S$ be a linear subspace of $R$ which described by linear ...
0answers
56 views

### Name of an archaic type of RSA padding (0BBBBBBB…)

In some legacy code, I encountered RSA signature padding in the following format (hexadecimal): 0B BB BB BB BB BB BB ... BB BB <hash> Is there a name for ...
1answer
62 views

### identifying presence of encryption of zero in additive homomorphic encryption

Lets say the server has corpus of ciphertext contains $enc(a),enc(b),enc(c), \dotsc enc(x)$. The encryption function is an additive homomorphic scheme (like Paillier). The server knows only the public ...
0answers
44 views

### How can I obtain the raw decimal value of an RSA key's modulus?

So maybe I'm thinking about this too hard, or maybe I'm missing a piece of information. We'll use Google for this example. Say I wanted to obtain the modulus of Google's current public key. Well I ...
1answer
65 views

### Why is Diffie-Hellman used instead of just RSA in key-exchange (TLS, IKE)?

Why should a key exchange protocol (such as in TLS or IKE) use Diffie Hellman? Why not just use RSA? For example: Alice picks a random session key, signs it, encrypts it with Bob's public key, and ...
2answers
145 views

### Should I add randomness at the end before AES?

Seen AES, changing a character drastically affects the encrypted text. I want to make it harder to decrypt AES I send. So, it seems this can be done by adding some special code and some random bytes <...
3answers
207 views

### paradox on fully homomorphic equality checking

Imagine, a client encrypts a corpus of data (say documents of text) with the public key of a Fully Homomorphic Encryption scheme (FHE) and outsources the data to an untrusted server.Now the client ...
3answers
65 views

### Is PGP's way of maintaining email security optimal? [duplicate]

I read a book called "computer networking: A top-down approach". It talked about how PGP creates an email message between Alice and Bob to maintain confidentiality, integrity, and authenticity. Let me ...
2answers
97 views

### Zero-knowledge proof system which is not proof of knowledge?

I have learned that a zero-knowledge (ZK) proof system can be constructed by making use of the three-color problem. In this particular case, the proof system also happens to be proof of knowledge (POK)...
1answer
67 views

### Using Pollard's lambda in a key-recovery attack on DH

I've become interested in writing an exploit for the OpenSSL vulnerability here (CVE-2016-0701). Running through the bullets describing the attack, I can follow up to the last bullet point. Reviewing ...
0answers
31 views

1answer
83 views

### RSA Digital Signature vs Elgamal Digital Signature

What are the advantages of RSA signatures against ElGamal signatures? Is there a situation in which it would be better e.g. to use RSA signatures?
1answer
147 views

The HMQV protocol has 2 "identity" fields $\hat{A}, \hat{B}$ that are used in the dual signature - and it tries to guarantee that any properly-generated session key is only shared by a single $(A, B, \... 0answers 44 views ### How to encrypt huge data using RSA? [duplicate] Is there any way to encrypt the huge amount of data using RSA? I was supposed it is possible but when I read some articles what I saw is that, this is bad practice or they say can only encrypt bit ... 1answer 59 views ### Plotting Running Times of SAT solver In the the paper "Efficient Methods for Conversion and Solution of Sparse Systems of Low-Degree Multivariate Polynomials over GF(2) via SAT-Solvers" there is a Figure that I can not understand and I ... 0answers 25 views ### Why SSH does not use a certificate authority in the same way as SSL [closed] SSL requires the use of a trusted third party -- the certificate authority to verify a public key presented by a server to a client. SSH on the other hand relies on the client having the server's ... 1answer 67 views ### How can I create pre-determined encrypted results? I want my encryption results to be the lyrics to Star Spangled Banner. The original text I'm encrypting would be, for instance, the menu to a local pizza place. I know what I want my passphrase to be. ... 2answers 134 views ### What is a purpose of reducing lattice basis? This may be too broad question but it is not. I have been studying lattices for few months now, more specifically I studied: lattice problems ($SVP$,$CVP$and etc.) lattice cryptography in post ... 1answer 36 views ### Is there a way to turn a PGP key into its semi-prime counterpart? From my understanding of PGP keys they use the RSA algorithms to encrypt/decrypt messages. So, I know that the RSA algorithms use a semi-prime number to encrypt/decrypt messages. So, what I was ... 1answer 68 views ### Are the following schemes based on a pseudo-random permutation secure? I am currently working on the following task: Let F be a pseudorandom permutation. Consider the encryption scheme for the message space$\{0, 1\}^n$defined as follows:$Gen(1^n)\$ chooses ...

15 30 50 per page