instruction stringlengths 32 27.2k |
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I'm looking at D.3.2 Verifiably Random Base Points of NIST SP 800-186. Looks like step 5 is there to ensure that $hashlen > bitLen(q)+1$ and (potentially) discard big $e$, so $t$ is distributed properly. However, the generation method won't work in if $hashlen < bitLen(q)$ (say SHA256 and Curve448). Is there any way to... |
I want to understand the limits of modulus switching in BFV.
Lets assume $q$ represents ciphertext modulus and $t$ represents plaintext modulus.
$q$ is set to a $60$ bit value and $t$ is set to $20$ bits value.
Now we are given a BFV ciphertext $c$ based on above parameter choices.
Also assume that due to holomorphic o... |
In Shoup's proof of the hardness of discrete log in the generic group in this paper, he mentions that:
At any step in the game, the algorithm has computed a list $F_1,\dots,F_k$ of linear polynomials in $Z/p^t[X]$ along with a list of values $z_1,\dots,z_k$ in $Z/s$, and a list $\sigma_1,\dots,\sigma_k$ of distinct va... |
Im building a backend for webapp(s), so that we can sell tickets for our events. The events ranges from 100-700 guests.
We sell tickets online and we would like to be able to scan the tickets at the entrance. This is done via a Barcode-128. But in the case it is not possible to scan the code, one should be able to type... |
I would like to get a correct understanding of the padding mechanism used in onion routing. The following is taken from the original paper of onion routing[https://www.onion-router.net/Publications/IH-1996.pdf].
Notice that at each hop the onion shrinks as a layer is peeled off. To
avoid compromised nodes inferring ro... |
In my cryptography course our teacher said that solving the discrete logarithm problem in a group of order $2^e$ is easy, and he gave us the following algorithm:
Let $G$ be a cyclic group with $|G|=2^e$ and $g\in G$ a generator. The following algorithm computes $x$ such that $h=g^x$:
Precomputation: $g^{-1}=g^{n-1}$.
... |
I'm going to use NTRU as post-quantum public-key encryption algo in my project.
I've googled attacks on NTRU and found a lot of them
but since I'm new to NTRU and don't understand the math used, and could not conclude whether NTRU is still secure, if yes which parameter sets are secure?
For 256bit security, I found EES... |
I'm solving a kernel ridge regression through a federated learning way.
Equation to solve the kernel ridge regerssion is dot((K+lambdaI)^-1,y).
So the aggregator of the problem knows the matrix A=(K+lambdaI)^-1.
But it cannot know the value of the labels y. So my idea was to encrypt the vector of labels y and apply inn... |
I am trying to understand the basic ingredients needed to conduct various types of cryptanalytical attacks.
For instance, I understand that for Ciphertext-Only Attacks (COA) an attacker only has access to ciphertext.
With Known Plaintext Attacks (KPA), attackers have some ciphertext and possess or deduce with reasonabl... |
If the LUKS header is removed from the LUKS partition, will this make the brute-force attack much more difficult? Can software tell which type of partition is it?
|
Help me please.
Consider specific primes $p = x^{d} + 1$ and $q = x^{e} + 1$ for some $x, d, e \in \mathbb{N}$. Can their product $n = pq$ be factorized faster than the product of general primes ? In other words, is there a factorization algorithm that is more suitable for such $p$, $q$ than the state-of-the-art algori... |
Are the methodologies (hard problems being used to secure the encryption) in post-quantum algorithms inherently slower than what we have right now? If not, why weren't they used initially?
|
I am confused on the definition of GAP SVP. The problem states that for a fixed $\gamma \geq 1$, given a basis $B$ of a lattice and a $d>0$, GAPSVP asks to determine if $\lambda\leq d$ or $\lambda > \gamma d$. My confusion is that what if $d<\lambda\leq \gamma d$? What would be the answer of GAP SVP then? I read from M... |
Recently, I've had an exchange with Lorenz Panny about Xifrat. He says, that the quasigroup that I use can be linearized and then attacked, and he provided a script that linearized the quasigroup. His result is as follow:
f:
2 0 4 3 5 7 1 6
1 5 3 4 0 6 2 7
7 4 0 5 3 2 6 1
0 2 7 6 1 4 5 3
3 6 1 2 7 5 4 0
6 3 5 0 4 1 7 2... |
I need to parameterize some PRNG, let's assume I need 32-bit numbers. But when numbers doesn't look very random it gives bad results. The creators of SplitMix had similar problem (note that from what I understand they didn't solve it right):
https://www.pcg-random.org/posts/bugs-in-splitmix.html
So I need a function wh... |
Let's suppose I want to generate a 2048-bit key from a hash function with security up to 512-bits (such as Blake2b).
I take 4 high-resolution photos, hash them with a hash output length of 512-bits and concatenate all the hashes generating a 256-byte (2048-bits) key.
Will this scheme safely generate a key with real sec... |
There are similar questions about secret S-box(es), but none of them about secret Blowfish (or any other canonical Feistel cipher) S-Boxes, only about secret AES S-Box.
Let's suppose that instead of using Pi hexadecimal number in Blowfish S-Boxes, I use my own S-Box taken from /dev/random and keep it secret.
Blowfish m... |
Let $g\in G$ and $h\in H$ be two group generators. Given a list L of m group elements, where $L=(L_1,...,L_m)$, a prover wants to convince a public verifier (namely, a verifier who only has public input) that one element $L_i$ in the list $L$ (without revealing i) can be produced from a public element $ u =u_i$ (where... |
For my project I used Henon map to generate (pseudo)-random number. I used the following code to generate the matrix of (pseudo)-random number.
def generate_by_henonmap(dimension, key):
x = key[0]
y = key[1]
# Total Number of bitSequence produced
sequenceSize = dimension * dimension * 8
bitSequence ... |
I'm new to this. Please be kind. I have a theoretical question that I would like sanity checked:
Bob and Alice are doing RSA signing without a hash function -- just putting a message in, and getting a signature out.
The messages Bob and Alice are sending each other are random numbers.
Without a hash function involved a... |
Until recently, I only knew about SMPC* and FHE, but now I just encountered the term NISMPC. I was wondering what is their difference and what is their difference in their use cases?
Sometimes in bibliography, SMPC is referred to just as MPC referring to the same thing.
|
Let's suppose I take a data block of 64-bits and use it as an entry in a (big) S-box, and keep the S-box secret. S-box would be the "key". For "decryption" I just enter the result of this operation in the S-box again to get the "plaintext"
For making all the blocks different each other in a sequence of them I would use... |
My understanding of the Even-Mansour cipher is the following:
We draw a random permutation $P$ from the set of all permutation $P: \{0,1\}^n \rightarrow \{0,1\}^n$. This permutation is public.
We generate two random keys $k_1, k_2 \in \{0,1\}^n$.
To encrypt a message $m \in \{0,1\}^n$, we compute $E_{k_1, k_2} = P(m \... |
-RFC4880 refer to DRBG at https://www.rfc-editor.org/rfc/rfc4880#section-16.2
-Could we apply other PRNG such as enocoro/photon for pgp?
|
During my research on a java application, I discovered that the nextInt(64) function of the java.Random() class is used to generate the encryption key.
The key size is 16 bytes. I know that this generator is not recommended because it is vulnerable. Especially in this case, the value of each byte of the key is selected... |
In Distributed Key Generation(DKG), why is there a need to actually create a master secret which can then derive into a single public and private keypair(for signatures) and a secret key(encryption)?
I would like experts here to explain to me (explain in a layman's way) because it seems to me that having a master secre... |
I perform the following commands because I need to decrypt a file -encryption key file- (which is longer than module):
cat key.enc | base64 -d > encryptedrawfile.txt
openssl rsautl -decrypt -inkey privkey.pem -in encryptedrawfile.txt -out key.txt
I obtain the following key.txt: ’àÝ g ™`çïrM¡.€:
Now I need to use encryp... |
I am a last-year master student in pure mathematics and I am working on my thesis. I am working on a connection between lattice-based encryption and Ring LWE and between Ring LWE and Homomorphic encryption. For the second part, I manage to find an appropriate paper to provide me with some information. However, with th... |
After some google research, I have found out the IV used in AES 256 bit encryption must be a 128 bit key.
My AES256 encryption is processed with key of random 256 bit key and IV generated of text string.
I am thinking about MD5 to generate such key, but MD5 seems outdated.
So Should it be okay if I use SHA256 generate ... |
What are the main differences between the Fast Fourier Transform (FFT) and the Number Theoretical Transform (NTT)?
Why do we use the NTT and not the FFT in cryptographic applications?
Which one is a generalization of the other?
|
Answers to question RSA key length vs. Shor's algorithm suggest that e.g. 2048 bit RSA encryption would be trivially broken with 4099 qubit quantum computer using Shor's algorithm (best known implementation of the algorithm requiring 2n+3 qubits).
Is this really true? If I've understood correctly, the number of gates (... |
I'm dealing with Galois fields $GF(2^{8})$ and need help finding a
polynomial $r^{-1}(x)$ such that $r^{-1}(x) r(x) \equiv 1 \mod m(x)$, where:
$m(x) = x^{8} + x^{4} + x^{3} + x + 1$
$r(x) = u(x) - q(x) \cdot m(x)$
$u(x) = s(x) \cdot t(x)$
$s(x) = x^{7} + x^{5} + x^{4} + x$
$t(x) = x^{4} + x^{2} + 1$
Thus:
$u(x) = ... |
Let $\{0,1\}^*$ be the set of finite $\{0,1\}$-strings. Then SHA512 can be viewed as a map $s: \{0,1\}^*\to \{0,1\}^{512}$.
The pidgeonhole principle implies that there is $y\in \{0,1\}^{512}$ such that $s^{-1}(\{y\})$ is infinite.
Is there $y\in\{0,1\}^{512}$ with $\emptyset \neq s^{-1}(\{y\})$ and $s^{-1}(\{y\})$ is ... |
In an edit to an answer by user forest, it was mentioned that there has been a new attack developed for lattice-based cryptography. I thought lattice-based cryptography is a fairly well established way of providing quantum-computing-proof security, and that the only thing left to do is developed a standardised system a... |
If A has a certificate issued by a CA_X, certainly A should have the private key of
the certificate. My question is, does A generate the private key by itself, or , the
private key is generated by CA_X, and somehow is sent by the CA_X to A?
|
Here is the use case: A uses B's public key to encrypt a message and sent it to B. In later stages, a new member C joins and B would like to let C be able to see this encrypted message (i.e., give the decryption ability to C) without sharing his/her private key or letting A encrypt the message again using C's public ke... |
I'm studying Impossible Differential Cryptanalysis of SPECK paper and I'm having trouble understanding the differential diffusion property of addition in page 19 which is as follows:
can someone explain what that property means or what symbol k|∆x[K] means?
|
I am searching for a scheme supporting group signatures and at the same time permitting the blinding of the message-signature pair. Let me explain.
There is a certification scheme proposed by Verheul: if we have message that is a public key, say $\texttt{pk}(A)$, and a signature $\texttt{sig}(\texttt{pk}(A), s)$ made w... |
Suppose we are working with a cipher with the same general structure as AES.
I want to attack the cipher in the following way: suppose that the differential holds only for the first round (much higher probability than wanting it to hold for all rounds from the first to the penultimate), recover the first subkey, then p... |
I was just thinking about this and couldn't seem to find anything on it online.
So the idea I had was this:
Generating a random key of some length. Then hashing this key with SHA256 (or something of similar security), then looping through each byte of the hash and each byte of the text and doing an XOR operation with b... |
I was reading Kipnis' and Shamir's paper on Cryptanalysis of the HFE Public Key Cryptosystem by Relinearisation and I wanted to implement the example at the end in Octave without using any additional packages (e.g symbolic ...). I would like to create an algorithm that solves systems of linear equations over finite fie... |
I am building a encrypted messaging app over tor network and currently I'm struggling on using tor generated ed25519 private key to sign and verify any message.
Below piece of code works with a 32 bytes key however after skipping 32 header bytes of hs_ed25519_secret_key it fails to verify the signature on below cases:
... |
To be more precise, in the books I sometimes see that they just require you that the order of your elliptic curve is $|E| = fr$, where $f$ is some small integer with possible factors, but $r$ is a large prime. I know that this is ok when working with ECC since, for example, the ECDLP is as hard as the largest prime ord... |
In a public key system, Alice sends Bob separate messages telling him information about the time T and place P they would meet, encrypted with Bob's public key. What is the most secured protocol:
A --> B : {T},{P}
or
A --> B : {T,P}
?
In other words, which one is most secure: sending separate messages with different ... |
Suppose I have a 32 bit CRC function $\text{crc32}(x)$ that satisfies all the properties of a CRC. Suppose also that I am a lazy developer who wants to create a 64 bit CRC function but doesn't want to actually have to implement another CRC, so I design a function
$$ f(x)= \text{crc32}( {\tt{"}\tt{foo}\tt{"}}\ ||\ x ) \... |
I am doing an independent research in cryptography. I have designed a post-quantum secure pseudo random function.
Just constructing a PRF will not help me to publish in reputed journals. I was thinking to use the PRF I designed as a building block to build some other primitive?
Can someone suggest me something? In whic... |
I have been studying Wieschebrink paper "Cryptanalysis of the Niederreiter Public Key Scheme Based on GRS Codes". In the paper a cryptosystem using GRS codes is exhibited with an attack proposed to the cryptosystem, this one being the Sidelnikov-Shestakov attack (well, actually a reformulation from the original one tha... |
I have an existing RSA key pair, how to 'derive' a different key pair based on the existing one so that the encryption decryption functionality remains but the original key isn't interchangeable with the 'modified'/'derived' key?
|
I am using the NIST SP 800-22 to evaluate the performance of the Random Number Generator.
NIST SP 800-22 has a total of 15 tests. In each test, it has a recommendation for the size of the tested sequence.
For example, in the Discrete Fourier Transform (Spectral) Test :
"It is recommended that each sequence to be teste... |
I have a string $S$ of length (say) 34, that I know the first (say) 24 bytes of, but not the last 10. I also have the 10-byte error correcting code $RS_{44,34}(S)$ in full. Do I have any hope of recovering $S$?
The amount of information of $S$ that I'm missing far exceeds the theoretical guarantee of Reed-Solomon (whic... |
Page 33 of The Algorithmic Foundations of Differential Privacy gives two examples where a composition of mechanisms can be viewed as a vector-values output, histograms, and fixed counting queries, where the privacy bound can be analyzed by considering the sensitivity of the vector-valued output.
I was wondering about a... |
Blowfish splits a 32-bit word into 4 bytes and insert each byte as an entry in a S-box.
Let's suppose I do the same but with an entire word, 32 or 64-bits. MARS block cipher does the same with 32-bit words.
Does it consume the same cycles per byte as inserting a single byte?
|
A rule 30 cellular automaton produces chaotic output from a very simple rule and therefore can be used as a pseudo-random generator (but not a cryptographically secure one).
One of the problems is that there are "black holes", for instance the constant 0 bit-vector gets mapped to itself, and the constant 1 vector gets ... |
Consider the problem of distinguishing between polynomially many samples of either
\begin{equation}
(x, b, As + e) ~~\text{or}~~\left(x, b, ~Ax + b\cdot(As + e) + e'\right).
\end{equation}
Here, $A$ is a public matrix and $s$ is a secret vector chosen uniformly at random. $e$ and $e'$ are Gaussian errors. $x$ and $b$ ... |
In the dual lattice attack of Espitau, Joux and Kharchenko (On a dual/hybrid approach to small secret LWE), the authors propose distinguishing (and subsequently recovering secret values) of LWE samples $(A,\mathbf b)=(A,A\mathbf s+\mathbf e)$ by finding dual vectors $(\mathbf x^T|\mathbf y^T)$ such that components of t... |
For the following cipher, what is the probability of someone without the private key generating a valid public key, using only information from a list of $k$ public keys previously generated with the private key?
This is the cipher:
To generate the private encryption key, $Y$: Let $X$ be an $n$ by $i$ matrix of random ... |
I'm looking at the FIPS-186 standard. On page 88, it gives a table recommending the size of the base field for the elliptic curve versus the order $n$ of a point on the curve. The numbers don't seem to make sense. For example it says if the bit length of $n$ is between $161$ and $223$, then the bit length of the ambien... |
I'm trying to find a Feistel cipher in which the subkeys are constructed badly so that a meet in the middle attack will compromise its security. I thought about trying out a cipher where all the subkeys are equal but that didn't really lead to anything. I know that in general you want ciphers to not be linear in their ... |
This problem appeared in a past exam paper.
In PAKE (password authenticated key exchange) protocols, $A$ and $B$ authenticate each
other by knowledge of a shared password that is too weak to allow an attacker to try out
repeated guesses to try to find it by knowing how a single message of the protocol was
constructed. ... |
Can I decrypt ciphertext from AES-CBC encryption, if I have the key and ciphertext only?
|
I am trying to understand the noise growth due to multiplication in BFV encryption.
As explained in section 4 and equation 3 of this paper: https://eprint.iacr.org/2012/144.pdf.
I couldn't follow what is $r_a$ and $r_r$ is in their equations.
Also how they are bounding the values of all rounding errors?
Also is there a... |
In Schnorr signature (R, s), R is used. But in ECDSA signature (r, s), r is used, which is the x-coordinate of R. Why the difference?
|
I believe I have found insecure usage of AES-CFB8 in an application I am working on and would hope someone could explain how and why this is insecure and what an attacker could do such as key recovery as that would be the worse result for this protocol.
Basically AES-CFB8(explicitly without padding) is used to encrypt ... |
What is the difference in key generation with commands below?
openssl genpkey -algorithm RSA -out key1.pem
key1.pem content:
-----BEGIN PRIVATE KEY-----
...
-----END PRIVATE KEY-----
openssl genrsa -out key2.pem
key2.pem content:
-----BEGIN RSA PRIVATE KEY-----
...
-----END RSA PRIVATE KEY-----
|
Okay so I've got an assignment for cyberlaw and this could be irrelevant to the question. But I have a situation where someone signed a a will using an advanced electronic signature, but this signature was separate from the will itself. So two different documents: (1) signature.txt and (2)FinalTestament.txt.
If these t... |
Or more general each member can be part of up to three 2D locally euclidean planes of 2 different dimensions each.
(each of those planes is cyclic in two orthogonal directions, like a torus)
Given just one member it could look like a node network:
(just one node with some neighborhood displayed here. Those neighbors h... |
I was playing a game on cryptography where I encountered this problem:
Hashed Value of password: 24 109 76 35 22 94 83 25 106 104 73 87 56 38 56 50 10
92 58 84 44 88 24 112 125 121 125 43 122 55 106 54
The password is made of letters between 'f' and 'u'. The password is
in alphabetical order. For hashing, the passwo... |
I understand the theory behind Hastad's broadcast attack.
Namely if we have three encrypted messages with the exponent e=3:
c1 = m1 mod n1,
c2 = m2 mod n2,
c3 = m3 mod n3
Then we can use the Chinese Remainder Theorem to find
c = c1 mod n1,
c = c2 mod n2,
c = c3 mod n3,
c = m^3 mod n1*n2*n3
and since n1 * n2 * n3 is t... |
is Client Puzzle a challenge-response variant of Proof-of-work? I am kind of new to crypto, sorry if the question is kind of dumb. If it's not can you give examples of algorithms that implement the idea of a challenge-response variant of proof of work? And can you explain why the Client Puzzle is not challenge-response... |
I have a rough idea of how STARK work, but I want to know which part makes them quantum secure. Is it because when the prover generates the proof they use the random number from the Merkle root, which cannot be guessed by a quantum algorithm?
|
It's common knowledge that the NSA, before publication of DES, tweaked the algorithm to improve its resistance against differential cryptanalysis. Schneier writes some of this on his blog, for example ("It tweaked the algorithm, and it cut the key size by more than half.", https://www.schneier.com/blog/archives/2004/10... |
Is there a possibility to encrypt a message that is a concatenation of an encrypted message and another message ( encrypt_message + message )?
|
Can the combination of X25519 ECDH and NTRU in OpenSSH 9.X defend me against quantum attacks?
Why is it believed that this combination is secure?
|
I am an FPGA engineer and my last experiences were related to digital communication implementation. I am about to start an experience for the cryptography market.
In digital radio communication, FPGA technology is common and viable in "niche" markets: modulators for broadcast or space telemetry for example. Some are no... |
I have the following pseudo code considering a ransomware methodology to encrypt files:
cFile = AESEncrypt(sessionKey, pFile, OFB, iv)
keyBlob = AESEncrypt(masterKey, sessionKey, OFB, iv)
ivBlob = AESEncrypt(masterKey, iv, ECB, null)
Aes 128 bytes is used for sure.
I don’t have information about master key, session key... |
I've found ECDH and ECIES, but those both require Alice to know Bob's public key and Bob to know Alice's public key in order to derive a shared secret.
Now assume Bob knows Alice's public key $A$, but Alice does not know Bob's public key $B$. Is there an Elliptic Curve encryption scheme where Bob can encrypt a message ... |
I've come across this particular design where I have one file encrypted.
Then multiple people may want to access the file and I want to generate an individual key for each person, but each individual key should be able to totally decrypt the file.
Is there some encryption design that allow that?
Regards
|
Some of the most widely-used/advanced cryptography products these days - AES and SHA3 - were invented by Belgians. It seems that fact is hardly a coincidence. Since I'm a complete layman, I can make the connection but can't draw the big picture. Why are they so good? Do the Belgians have a tradition leading back centur... |
When performing Shannon Entropy analysis on something like an RNG or a file, you must:
Select a symbol bit length and number of samples would will perform analysis on at a time (IE: windows size)
Read the input till the window is full
Perform a histogram on the collected symbols
Take the histogram output and calculate... |
I'm trying to develop a Key Distribution Protocol to share symmetric keys in RFC 6238 (OTP).
I started with RFC 6063, but this protocol is developed over old and known insecure algorithms like PBKDF and do not take advantage of more advanced hardware like smartphones (the device I will use to produce OTPs)
The main ide... |
When I sign a message with a private key, and I get a message signature, how is it that I'm able to - using the corresponding public key - verify that that message/transaction signature must have been produced by the person holding the private key behind the relevant public key?
My understanding is that with private/pu... |
Setup
Recently, I became interested in simulation based proofs in the context of secure two party computation. I read some book chapters (from Secure MPC and Secret Sharing and Foundations on cryptography volume 2), papers (most importantly How To Simulate It), and posts from cryptography stack exchange, but I still do... |
In my criptography course I was given the following exercise:
ElGamal proposed the following digital signature scheme using discrete logarithms over a field $\mathbb{F}_p$, where $p$ is a large prime.
Step 1) Everybody agrees on a prime $p$ and a generator
$g$ for $\mathbb{F}_p^*$.
Step 2) A (and all other uses) choo... |
How can I write a program in python to predict the random key (urandom) that is used for encryption? I tried to search and I couldn’t find anything related to guessing and predicting urandom in python
|
Often data is encrypted using Symmetric Ciphers and Symmetric key is shared with recipient by encrypting it with recipient's Asymmetric Public Key. NIST Special Publication 800-56B, Revision 2 section 9 defines RSA KTS-OAEP to establish keying material between sender and receiver. Is it really necessary to use RSA OAEP... |
I've been working on a AES256-GCM implementation (in Java).
I'm a little bit stuck on the part where i need to decide how often i need to rotate my key.
I've got a lot of information from this posts:
Safety of random nonce with AES-GCM?
And the website if refers to: https://www.imperialviolet.org/2015/05/16/aeads.html
... |
I stumbled across this correctness of a scheme:
$e(g^r, H(id)^x) = e(g^x, H(id))^r = e(g^x, H(id))^r$
and have a hard time following the properties of the bilinear pairing. Does anyone know the "rules" for such pairings or where to read about them?
As far as I have learned I know that:
$e(g^{xy}, g) = e(g,g)^{xy} = e(g... |
A prover has the following value:
$$C = (h^ag^x)^b$$
and he needs to prove in zero knowledge to a verifier that $x < t$, for some public threshold $t$.
The verifier knows $h$, $g$, $C$, and $t$. The prover knows everything. Essentially, it is the following relation:
$$\{(a,b,x)\ |\ C = (h^ag^x)^b \wedge x < t\}$$
I kno... |
Most of the answers I can find date to years back where the first collision(s) were found, but hardware mainly GPUs have progressed a lot in the past few years (with for example the new line of 3090s coming).
How easy is it to do so right now?
|
What are some standard assumptions made in showing the security of a block cipher?
For example, is it commonly assumed that $P\not=NP$? To this end, are there any block ciphers whose security does not rest on the assumption that $P\not=NP$, and if so what are the assumptions?
Furthermore, do there exist any block ciph... |
https://en.wikipedia.org/wiki/Paillier_cryptosystem
Paillier cryptosystem exploits the fact that certain discrete logarithms can be computed easily.
If I were to select $g \in \mathbb{Z}_{n^2}^*$ where $n$ divides the order of $g$, then the discrete log is easy (w.r.t base $g$) if I understand correctly.
But if I wer... |
It seems that neural cryptography is an interesting research topic and there are some important contributions published in the last years.
The proposed algorithms are suitable for symmetric key generation starting from the common hidden weights, thus representing a possible Diffie-Hellman substitute.
As far as I unders... |
Imagine the following scenario:
In a given cryptocurrency, privacy should be as high as possible.
For this purpose, a new account with a new address is created for every incoming transaction (the address is the public key of a private/public key pair). However, users are not always online to generate new accounts with ... |
Consider the following scenario:
We have two agents, A and B.
B needs to prove that they know a secret to A, without sharing the actual secret.
e.g.: A needs a way to de-duplicate the secrets they receive from B, but they don't need to know the actual secrets. (and B does not want them to know)
Think of it like sharing... |
I found this question while preparing for exam. The question is
Q)Suppose, you and your friends have a few numbers of locks and you all want to share that numbers among yourselves securely using RSA based cryptosystem. You are using the private key as (5,27) and your friends are using the public key as (13,27). One of... |
I was doing some Microsoft Seal testing on my macbook pro (i7) and got following results
Coefficient mod $q = 100$ bits and Polynomial degree $n= 8192$
Ciphertext-Plaintext multiplication takes 0.211 milliseconds
Ciphertext-Ciphertext multiplication takes 24 milliseconds, when I pick 5 RNS moduli for coefficient mod.
... |
In the Bleichenbacher attack, when the $|M_i−1| = 1$, we should choose $r_i >= 2(bs_{i-1} -2B)/n$ in order to increase the search performance. I don't quite understand how this $r_i$ value is calculated and how this can improve the performance. Anyone can help?
The above information can be found on https://eprint.iacr.... |
Let $s: \{0,1\}^* \to \{0,1\}^{512}$ be the SHA512 hash (where $\{0,1\}^*$ is the countable set of all finite $\{0,1\}$ strings.
Is it known whether $|\text{im}(s)|/2^{512} \geq 0.5$?
If yes, what is the largest $n\in\mathbb{N}$ such that $|\text{im}(s)|/2^{512} \geq 1 - (1/2)^n$?
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How is it possible to recover RSA private keys considering that weak LCG (random number generator) is used?
I have some other keys (Public and private created with the same generator) and also some crypt texts encrypted with both keys.
It is relevant to highlight that there is no clue about the algorithm used to create... |
I am trying to verify an Ed25519 implementation, but I can't find any test vectors for the curve points. All test vectors focus directly on signature constructions (EdDSA).
I tried to use https://asecuritysite.com/ecc/nacl07 but that seems to give the wrong results. For instance, it reports that the affine coordinates ... |
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