instruction stringlengths 32 27.2k |
|---|
I am trying to show that UF-naCMA doesn't imply UF-CMA. UF-naCMA is actually defined as UF-CMA but the adversary should send $q \in poly$ messages $m_i$ chosen non-adaptively (i.e. all at the same time) before obtaining the public key. Then, as in UF-CMA in order to win he has to forge a valid $(m^*,\sigma^*)$ with $m^... |
As we know, the IV and the output of SHA-256 are identical in size. Suppose the input value to the SHA-256 is completely transparent. Is there any correlation between IV value and output? Is it possible to limit the output space?
I would appreciate it if you can introduce any source - article or manuscript in this spec... |
According to the Curve25519 website:
Computing secret keys. Inside your program, to generate a 32-byte Curve25519 secret key, start by generating 32 secret random bytes from a cryptographically safe source: mysecret[0], mysecret[1], ..., mysecret[31]. Then do
mysecret[0] &= 248;
mysecret[31] &= 127;
mysecret[31] |= 64... |
On my old laptop, ChaCha20 is quite a bit faster than AES as there is no hardware acceleration for AES. But for disk encryption AES based schemes seem to be the only option, as a stream cipher like ChaCha20 cannot directly be used for disk encryption. Is it possible to use ChaCha20 in some other way/mode to make it sui... |
Is there any way in which classical computers oculd end up breaking ECDLP. I read that GNFS could through prime factorization, but I am not sure if I understood this properly.
|
I am presented with the following problem:
Given a set of matrices $M = \{A^i_{m,n} : 0 < i < 101 \}$ design a procedure to compose all of them into one encrypted matrix $E_{m,n}$ and later decompose (decrypt) it into the initial set. The procedure should be as difficult to break as possible (quantum-resistant preferab... |
This may be a very basic question.
I know that symmetric key algorithms use the same key to encrypt and decrypt plaintext and ciphertext.
However, it seems that hash functions are often classified as symmetric key cryptography.
Even though the key is not used in the hash function, from what point of view can it be clas... |
I'm studying the post-quantum cryptography (PQC).
While studying hash-based pqc, I read a thesis about Winternitz one-time signature scheme (W-OTS). What is the exact definition of "One-time Signature (OTS)"?
There is lots of papers and posts quote the word "OTS", but anybody didn't write the definition of OTS.
|
What issues do yall see with the following in terms of key recovery and related key attacks:
RC4 used to "sign" a nonce:
3 byte nonce concatenated with 16 byte long term key > RC4 Keystream Generator > 259 bytes keystream output
Discard first 256 bytes of keystream leaving only last 3 bytes "Signature"
3 byte Nonce / 3... |
I'm working on a friendly tower finite field implementation for educational purposes. The library should allow easy building of tower fields from smaller ones - a user may define $\mathbb F_q$ and then build a tower field such as $\mathbb F_q \rightarrow \mathbb F_{q^k} \rightarrow \mathbb F_{(q^k)^m}$ and add/multiply... |
My understanding is that iOS FaceID/Fingerprint for example use an underlying mathematical representation of the biometric features.
Is it possible to generate a key pair from this representation and re-generate the same key pair from the same input but on a different device for example?
I only found this old thread fr... |
The protocol would look like this:
User creates account and provides username, static public key
User logs in by sending username
Server responds by sending an ephemeral public key
For the duration of the user's session, all requests must be accompanied by the ECDH shared secret between user-static and server-ephemera... |
In university, I'm currently learning how to use Scyther to model security protocols. Currently I am trying to understand what is happening in an example protocol given to me which is:
# Key Establishment Protocol
#
usertype SessionKey;
protocol ke11(I,R,S)
{
role I
{
var Kir: SessionKey;
sen... |
I was trying to come up with simple padding functions for the RSA, then trying to break them just to have a better understanding of why we need all the pieces used in the RSA OAEP... So, I am considering the following.
Let $N = p\cdot q$, $pk = e$ and $sk = d$ be the RSA parameters and keys, as usual.
Now, let $n = \lc... |
I rent a room in a building. There are also 9 others who rent other rooms in this building. Just like everyone else who rents a room I only have one key of this building.
With my key I can open the front door of the building. Just like everyone else who rents a room can with their key. However, only I can open the door... |
Suppose that Alice has an X25519 key pair $\{S_A,P_A\}$ (secret and public key, respectively). Using randomly selected X25519 public keys $\{P_*\}$ (such that $P_A\notin \{P_*\}$), Alice calculates several values $X_* = \operatorname{X25519}(S_*,P_*)$.
She then repeatedly flips a (fair) coin. Each time, if the result i... |
From here - Batch Opening of KZG PCS
One can prove multiple evaluations $(\phi(e_i) = y_i)_{i\in I}$,for arbitrary points $e_i$ using a constant-sized KZG batch proof, $\pi_I = g^{q_I(\tau)}$, where
\begin{align}
\label{eq:batch-proof-rel}
q_I(X) &=\frac{\phi(X)-R_I(X)}{A_I(X)}\\
A_I(X) &=\prod_{i\in I} (X - e_i)\\
... |
In this question, we restrict to RSA public keys $(n,e)$ such that
$n$ and $e$ are odd, $3\le e<e_\max$, $e<n$
Note: For some old Windows API, $e_\max=2^{32}$. In FIPS 186-4, $e_\max=2^{256}$. Other requirements are from PKCS#1.
For all $m\in[0,n)$, it holds $m^e\bmod n=m$. That is, textbook RSA encryption is the ide... |
How should I generate the remaining keys when performing subkey generation in AES encryption? I generated keys 0 and 1 first, but the other keys I generated later were wrongly generated, so what steps should I do to generate the rest?
I know the steps of shifting rows and mixing columns but I don't know what to use whe... |
Let $G:\{0,1\}^n \leftarrow \{0,1\}^{2n}$ be a PRG. Establish whether the following PRG candidates $$G^{'},G^{''}:\{0,1\}^n \leftarrow \{0,1\}^{3n}$$ are secure or not:
$G^{'}(s)=(x⊕y,u,v)$ where $(x,y)=G(s)$ and $(u,v)=G(y)$;
$G^{''}(s)=(x,y ⊕ u,v)$ where $(x,y)=G(s)$ and $(u,v)=G(y)$;
This was in my exam today and ... |
The iOS version of Signal application (not the protocol) includes a form of key wrap that I've never seen elsewhere: SHA256-HMAC-SIV.
It's used to encrypt your master key with your pwHash(PIN) before sending it to signal.org's Key Backup Service.
So far as I can tell, it does the following:
SHA256-HMAC-SIV(kek, raw)
ke... |
I wonder if it's possible to do public key authentication (preferably not vulnerable to replay attacks) before modern computers became a thing (e.g. in a medieval setting).
Specifically:
Authentication can be done in a reasonable time by hand.
Brute force by hand requires unreasonable time. (But it may be possible wit... |
I have a question regarding the paper:
Andreeva, E. et al, Securely Release Unverified Plaintext in Authenticated Encryption , 2014
(DOI: 10.1007/978-3-662-45611-8_6)
AE schemes such as GCM [28] and CCM [40] reduce to CTR mode in the RUP setting. This is because the adversary does not need to forge a ciphertext in ord... |
In a WPA2 (802.1X) scenario, there are 3 entities -> Supplicant (client), Authenticator (router) and Authentication server (Radius server). Radius server performs the authentication process and, as far as I understand, in the authentication process, the router works only as a proxy.
If an attacker is able to sniff the ... |
Does there exist a lattice in $\mathbb{R}^n$, with an independent generative family $(b_1, \dots, b_{n+1})$ of $(n+1)$ vectors (without any loss of generality I suppose $(b_1, \dots, b_{n})$ is a $\mathbb{R}$-basis), for no generative family of size $n$.
I know:
If these vectors are in $\mathbb{Q}^n$, then the answer... |
It's well known that two parties, Alice and Bob, can flip a fair coin using commitments.
Alice picks a random number $a \in \mathbb{Z}_q$ and computes $c_a = Com(a, r_a)$ where $r_a \xleftarrow{R} \mathbb{Z}_q$. She then sends to Bob $c_a$.
Bob does the same, pick a number $b \in \mathbb{Z}_q$, and compute $c_b$ and s... |
What goes wrong if we use the same key k in deterministic counter mode to encrypt two different plaintext messages m0 /= m1.
It is not true that c0 = c1, because we XOR output of m0 with input of m1 in counter mode. As a result, c0 cannot equal c1, and c1 cannot be said to be the same as c0.
Could this be true?
Attack... |
I'm not fully sure what the most accurate terms would be to describe what I'm looking for, but here's the gist:
Let $u_1, \cdots, u_n$ be the users from a set of users $U$. Users may or may not submit some data $d_{u_1}, \cdots, d_{u_n}$ into my database, which I'll model as a set of data $D$. I want to be able to det... |
The Inhomogeneous Short Integer Solution (ISIS) problem is as follows: given an integer $q$, a matrix $A\in \mathbb{Z}^{n\times m}_q$, a vector $b\in \mathbb{Z}^{n}_q$, and a real $\beta$, find an integer vector $e\in\mathbb{Z}^m$ such that $Ae=b\mod q$ and $0<\Vert e\Vert_2\leq\beta$.
if we assume that $n=m$ is this a... |
Does this research also work for breaking bitcoin ECDSA? If so, how many qubit will be needed for 256-bit elliptic curve key?
|
In one proof I show that, given a cyclic group $Z_{p}^{*}$ where $p$ is prime, and a set of information $X$ computing $y\in Z_{p}^{*}$ is as difficult as solving Computational Diffie Hellman (CDH) problem.
In another proof can I make the argument that as transformation $X \rightarrow y$ is proven to be CDH, given $X$, ... |
Since AES needs IV to be random (unless fed by a unit test), I was wondering how to properly handle it.
I know that Intel/AMD now supports the rdrand64 function but I don't fully want to rely on that.
Can I safely combine multiple sources of randomness and SHA256 them to produce a random 256-bit number?
My sources of r... |
I'm working on a problem where I need to track some state that's 64-bit integers. It turns out this state can tracked by simply accumulating a sum of differences, which in my case turns out to naturally sum to zero:
$$s = \sum_k (b_k-a_k)$$
This is a "closure" relationship that relies on all the values being transitiv... |
The task is something like this. Alice must send Bob the money, but so that the amount remains hidden.
How can this be done if only "hiding" balances are stored in the blockchain? How can I prove to someone that my balance is positive after the transfer?
In other words, how can I prove to someone that the number x >0, ... |
Kyber and Dilithium are post-quantum cryptographic designs, but the resources are hard to understand. Is it possible to explain those ciphers to children?
|
I'm currently taking a computer security module in University and as part of a problem have been asked:
My thought for the question is that no it does not provide 64 bits of security strength. This is as (IV,C) is transmitted over the network meaning that if the signal were intercepted by an adversary IV can easily be... |
I am doing a RSA cryptography task where I need to decrypt a ciphertext but I am only given the ciphertext ,c, a public exponent, e, and a RSA modulus, n, which has two prime factors p and q such that |p − q| < 10000.
I am unsure of how to do this but I am given the hint of using a low exponent attack (although the exp... |
In some RSA libraries I've encountered, the P bit count is left shifted by some amount and Q bit count right shifted by the same amount. For example, if generating a 2048 bit key, the P bit count would be 1088 and the Q bit count would be 960, so the N bit count would still be the requested 2048, assuming appropriate ... |
Consider the following construction of a SKE scheme $\Pi^*=(Enc^*,Dec^*)$ based on a PRF family $F=\{F_k:\{0,1\}^n\rightarrow \{0,1\}^n\}_{k\in\{0,1\}^\lambda}$ and on a MAC
$ Tag:\{0,1\}^\lambda \times \{0,1\}^n \rightarrow \{0,1\}^\lambda$ with UF-CMA security.
Key Generation: The key generation algorithm returns a r... |
Is hashing a pseudo-random generated string of letters upper/lower + numbers 256 characters long with SHA256 insecure, in the sense that in any reasonable amount of time you can go from hash to original string?
Would using a more conventionally strong password hashing algorithm be necessary to still answer no to the ab... |
I am looking at this in the context of password hashing in PostgreSQL, specifically, the crypt function of the pgcrypto extension.
The PostgreSQL documentation refers to the Unix man page of the crypt function. The man page (man 3 crypt) of the crypt function states that it performs Trapdoor encryption. Now a trapdoor ... |
I am working on my master thesis which has as a main subject the CKKS algorithm. I am following the paper https://eprint.iacr.org/2016/421.pdf in which on page 8 it is mentioned that the encoding/decoding in the CKKS are isometric ring isomorphisms between $(S, \|\cdot \|_{\infty}^{can})$ and $(\mathbb{C}^{N/2}, \|\cdo... |
What is the significance of theoretical weaknesses?
Any real life incident where a theoretical weakness was ignored and later it compromised the system? Whats the dividing line between theoretical and practical weakness? Are there any other categories? How quantifies a practical weakness as what seems impossible for on... |
Consider a Schnorr group with order a prime $q$ sized for security against current computers (like $q$ of 256 bit); modulus a prime $p=q\,r+1$ large enough (e.g. 3072 to 32768-bit) that the algorithms of choice for solving the DLP in the group are Pollard's rho or Pollard's kangaroo, rather than Index calculus, Functio... |
An encryption scheme should be injective in the sense that each ciphertext should only be associated with at most one message, in order that decryption is unambiguous. An efficient signature verification scheme should be surjective in the sense that each message (equivalently message hash) has an associated signature, ... |
NIST's main recommendation for encryption/decryption mechanism is CRYSTALS-KYBER. Whereas, the BSI (German equivalent) chooses FrodoKEM.
As far as my knowledge goes both these mechanisms use LWE lattice problem for their cryptographic security.
Then what makes the two mechanisms different?
Is it just the parameterizat... |
All,
Recently, I came across a question on privacy for big data and AI.
IMO, big data privacy focuses on "anonymization" aspect where sensitive informatino such as Personal Identitfiable Information should be protected, while AI privacy focuses on "raw data stealth" where raw data should not be inferred or derived from... |
I am looking at the paper on Kate Polynomial Commitments.
On Page 7, VerifyEval, the verifier checks the following to verify commitment.
$e(\mathcal C, g) \stackrel {?}{=} e(w_i, \frac {g(\alpha)}{g(i)})e(g, g)^{\phi(i)}$
In the next line, the paper explains why this equality will be true if the commitment is in fact h... |
Is there any algorithm that I can check if point(G^9857) is more near to point(G^54) rather than point(G^448)?
|
I am new in Elliptic curve and I got a lot of knowledge through reading :) but I reached to NAF method as a scalar multiplication method, but don't understand how in this example get it:
Let k = 1234567 and its binary representation contains 21- bits:
100101101011010000111. In this
11 1′s and 10 0′s can be found resul... |
I’m sorry if this is already answered, however, regarding symmetric key components to create a symmetric key using xor
(So eg comp1 xor comp2 xor comp3 = key)
If in the case of an AES KEY, which goes through an expansion routine(?) If someone gets one of the values (who shouldn’t), what is the actual risk? It gives not... |
I have a simple question but I can't seem to find the answer of.
I know that
A 128-bit hash contains 32 characters since each represents a hexadecimal.
Similarly, a 64-bit hash would contain 16 characters.
However, if I had a 64-bit and 128-bit string consisting of letters (both uppercase and lowercase) and numbers ... |
In Wesolowski's VDF (verifiable delay function) a prover produces a pair $(x, y)$ and needs to argue to the verifier that the pair satisfies $y = x^e \pmod N$ for some $e$ computable to both. The verifier is compute limited and $e$ is really large, so cannot compute $x^e\pmod N$ herself. The prover needs to convince th... |
Given a list of base entities (B) with each of them having a universally unique identifier (UUID) of 128 bits.
I want to attach to them a list of ≤ 7 related entities (TE, UE, ..., ZE) with each of them having their own UUID. One requirement is that I should be able to get the UUID of the main entity from the related e... |
If I test the Pseudo Random Number Generator(PRNG) and it satisfies the serial test, it is not sure that the resulting distribution is uniform. Is my observation correct? If it is correct, what test should I do to be sure?
|
Suppose we define privacy as a game where a machine $M$ has a coin $b$, and on input $M_0, M_1$ always replies with encrypted $M_0$ if $b=0$ and encrypted $M_1$ if $b=1$. The adversary can send as many pairs $M_0, M_1$ as he wants. The goal is to guess $b$. If he cannot do better than guessing at random (i.e., with pro... |
CKKS is a levelled scheme, because the rescale $\lfloor\frac{x}{\Delta}\rceil$ operation requires truncating a modulus to be efficiently evaluated, and rescale is (usually) needed after every multiplication to control noise growth.
But I don't understand why rescale have to decrease ciphertext modulus. In residue numbe... |
I would like to implement a hash function $H1 \colon \{0,1\}^* \to \mathbb{Z}_p^*$ such that $p$ is a prime number and second fonction $H2 \colon \mathbb{Z}_p^* \to \{0,1\}^k$ where $k$ is a security parameter
what is the best way to implement them with SHA 256 or another hash function?
|
When researching about PQ KEM's I have come across two different definitions of indistinguishability under (adaptive) chosen ciphertext attack. IND-CCA (https://eprint.iacr.org/2017/604.pdf page 10, Kyber - https://eprint.iacr.org/2017/634.pdf page 3) and IND-CCA2 (https://eprint.iacr.org/2002/174.pdf page 4), the sec... |
I'm reading our school's notes for cryptography, and it does a good job explaining CBC and DES in detail, but it fails to provide good information on how they are related.
From what I've researched so far, it appears that CBC is essentially a series of block ciphers, and DES can be used for the block cipher encryption ... |
If I would like to focus on only one signature scheme, and only one encryption based on lattices in a pedagogical context (to introduce the concept of lattice-based crypto to people familiar with cryptography)?
Is it possible to consider only one cryptographic problem in this context?
|
In RSA, I want to know a way to be able to retrieve all possible plaintexts $m$ given a ciphertext $c$, $\phi(n)$, $n$ and $e$. The decryption exponent $d$ can not be generated due to the fact that $e$ is not co-prime with $\phi(n)$.
In fact, the $e$ I have is not even prime(it is specifically $1024$ in this case and t... |
I'm working with https://cr.yp.to/nistp224/library.html and trying to correctly format my integer e for the library. The doc states:
The integer e is 2^224 + 2^216(e[0] - 136) + 2^208(e[1] - 136) + ... +
2^0(e[27] - 136).
I already have an integer e in mind, but I've got it encoded as a big endian array of bytes. Wha... |
I have a problem where I have a table of various reencryptable/rerandomizable ciphertexts (Paillier, Elgamal, EC Additive Elgamal). Each row on a given table has the same structure, but each column potentially has its own cryptosystem. This shuffle gets executed several times on different tables with different number... |
I am self studying "A Graduate Course in Applied Cryptography" by Boneh-Shoup. I am stuck on the following problem.
Let $\mathcal{E}$ be be an encryption scheme where messages and ciphertexts are bit strings.
(a). Suppose that for all keys and all messages m, the encryption of m is the exact same length as m. Show that... |
I'm a student studying cybersecurity for the first time, and the part where our textbook explains using CCA attacks for RSAs seemed really unclear for me, so I am here seeking for clarification.
Our textbook quotes
if the attacker receives encrypted message c = m^e (mod n), they can multiply by the encryption of a ran... |
I understand how the Kate Polynomial Commitment Scheme Evaluation Proof works however, I don't understand what is the purpose of it?
In general, in a commitment scheme, Peggy commits to message & sends the commitment to Victor. The purpose of a commitment scheme is two fold
Once Peggy commits to a message, then she ca... |
My goal is to design an encryption scheme for the application so that the backend stores encrypted data and the whole process of encoding and decoding happens on the frontend. And you can be sure that even if the backend database gets compromised the data is impossible to decrypt.
I'm in no way an expert on the topic b... |
For example, if we run this openssl command:
openssl aes-128-ecb -a -in <(echo -n "AAAAAAAAAAAAAAAA") -K "deadbeefdeadbeefdeadbeefdeadbeef"
The output in hex looks like:
block 1 block 2
7a03acccf884d4ac38b7a2f3529806fa adfbc6ad78223f79cded6638d1d9802b
If I run it again and change the last byt... |
I am start learning about Elliptic curve and I read about Compression multipoint in curve which will be more efficient for saving more memory, I am looking for an example I can follow it with correct output.
|
I’m trying to understand the proposal presented in this papger zkKYC - A solution concept for KYC without knowing your customer, leveraging self-sovereign identity and zero-knowledge proofs.
The essence of the paper is on page 10 and specifically in the two sections zkKYC token and Validity proof.
According to the pape... |
I am trying to solve an rsa problem where we only know the public key (n,e) and the ciphertext c.
The modulus n is actually a prime number, so we can easily compute phi as phi = n-1.
But the problem is that e shares a common factor with phi, where gcd(e,phi) = 8 , where gcd = greatest common divisor. So this means we c... |
Let $E_{k}(P)$ be the AES-128 function with key $k$ and plaintext $P$, both 128 bits. I want to know if the following property is generally true for AES or if have I stumbled upon a special set of keys:
$$E_{k_1}(E_{k_2}(P)) = E_{k_1}(P) \oplus E_{k_2}(P)$$
|
I know that the message never directly changes those last c bits of the internal state (as seen in the image). And I also know that the capacity bits make the sponge construction resistant against collision and preimage attacks. How do the c-bits make it resistant against such attacks?
|
Say that in $\mathbb{F}_{999,999,000,001}$ I have an equation $0 = ax - b$ where $a$ and $b$ are random values from the field.
Is it possible to solve this equation for $x$ using the Extended Euclidean Algorithm without a brute force search?
If instead I was in a finite field with order as a 254 bit prime, would this p... |
Let's say I have a block cipher $E: K \times M \rightarrow C$.
Is the function defined by $\operatorname{Enc}(k_1,k_2,m) = E(k_1, m)\ \operatorname{XOR}\ E(k_2,m)$ guaranteed to have an inverse function $\operatorname{Dec}$?
If it has, then what is $\operatorname{Dec}(k_1,k_2,c)$?
|
I was practicing some questions on cryptography (newbie) and came across this question:
I know that Z26 means modulo-n arithmetic is used, but what does the superscript (3) denote? My guess is that the superscript represents the dimension of the square, key matrix. But, I would like it if someone confirms it for me or... |
Let
x = 100 - initial balance
M = 1,000,000,000
transfer amount final balance M+x
E(p-M) + E(M + x) = E(p - M + M + x) = E(p + x) = E(x)
producing correct proof of the fact that the final balance minus the initial balance is equal to the transfer amount
where E(x) = x*g,
g - generator of ellipt.curve,
p = ellipt. group... |
I want to produce a transaction log that is encrypted while being produced. I'd prefer asymmetric encryption. It is possible that my program will terminate without writing any closing blocks, so my output can't depend upon being able to write any end-of-file blocks the encryption scheme may require.
I can open new tran... |
Is it possible to receive from a party $I$ a signed message $M$ that can be presented to two independent other parties $V_1$ and $V_2$ as $M'_1$ and $M'_2$ in such a way that they cannot establish a correlation between $M'_1$ and $M'_2$, but that they can verify that the message was signed by $I$ and issued to the one ... |
A common method to mitigate the effect of rainbow tables is to add a string to the end of the user password before hashing, a process known as salting.
However, let’s say for example that someone uses a certain password across multiple websites which all salt their passwords, all use the same cryptographic hashing func... |
I am looking for a DRNG/DRBG (cryptographically secure) algorithm/function (which I can program into js). I am looking to use a DRNG as a seed generator for generating multiple, identical AES keys on separate client devices, sharing the seed for the DRNG securely between users. Basically, I trying to see if there are a... |
I was recently discussing with a friend how to instantiate something that requires a RO (with a potentially long output) in a practical implementation. Specifically, for a Fiat-Shamir transform.
The options I see are:
Hash function
PRF
CSPRNG
KDF/randomness extractor
...?
What primitive can be used, in what construct... |
I am trying to fix issues with a server where the server keeps freezing up and needs to be restarted. I recently started hearing about entropy and it importance to secure tls keys in linux. The one thing I haven't found in my research is, how much is needed/how to increase entropy on a linux server for TLS 1.2.
I belie... |
This is a pretty open question, so I'm mostly looking for gut reactions from experts more educated than I.
Given these assumptions which are easy to verify with a quick Google search:
One Time Pads need to be truly random to be unbreakable
Human beings cannot generate truly random numbers mentally
My question is: how... |
I am struggling to understand how messaging protocols (like Signal) are able to use perfect forward secrecy. My understanding is that the server generates temporary keys which are used in combination with a user's persistent keys in generating shared session keys.
But if the temp keys are discarded after the session en... |
Background
I have a degree in electronics engineering, I'm not bad at programming with many languages, but I'm not that good at cryptography, I'm just able to use that from libraries, and I understand just a few basic principles.
I'm evaluating the McCallum-Relyea key exchange protocol (the one used in the tang protoco... |
Please I do have a question as you know to sign a message the sender must first of all calculate the hash of the message and then encrypte it using his private key and then send it to the reciver and then the reciver will use the public key of the sender to decrypte the signateur. so how the reciver got the public key ... |
I want to create a self signed PKI for a couple servers I am running. I am finding tutorials with copy paste commands from openssl, and hand waving explanations that describe the general purpose of signing certificates, or 20 page papers on the algorithms used. However, I am really trying to understand the way certific... |
I wonder if a rotor machine similar to enigma can be considered secure by today's standards under four conditions:
A rotor machine which consists of 50 rotors picked out of a set of 100.
A rotor machine in which a letter can encipher to itself.
You can select the very same rotor multiple times.
No plugboards, no s... |
would compress and encrypt on data comromise security for PGP like application, would it be secure for use in Encrypted Messaging?
I have heard its safe for data at rest encryption , i have heard about CRIME and BREACH attacks on TLS, i am concerned if it would affect PGP like applications and the case of encrypted mes... |
DDH is believed hard for subgroup of $ℤ^*_p$ with order $q=(p-1)/2$ when $p$ is a safe prime chosen randomly.
What if $p$ isn't random: When parameters are shared, $p$ mightn't have been chosen randomly—primality can be tested, random sampling cannot—is DDH still believed hard, are any security concerns created/mitigat... |
We are using libsodium and regarding exchanging secrets we would like to use the so-called crypto_box (https://libsodium.gitbook.io/doc/public-key_cryptography/authenticated_encryption). Under the hood, ECDH is used. The problem is that it can be possible as well, that I encrypt this secret by myself. In that case, Ali... |
I'm new to crypto, and I've got an idea and I want to get some feedback if it's even a right direction. Let's say that I create a symmetric cipher by using an XOF with a salt and a secret key.
Something like that.
XOR(XOF(salt, secret), plaintext)
When I want to send somebody an encrypted message, I will send both the ... |
So, for my capstone project, I've been working on a cryptographic algorithm accelerator on an FPGA. While it did get approved, I've been suggested to work on a more application-based idea that could incorporate my accelerator, where its use can be justified. I'm trying to find examples where using FPGAs over Microcontr... |
This is a follow-up question to Mikero’s answer to Simulation-based proofs and universal composability proofs.
Let there be some protocol $\pi$ running between two parties $A$ and $B$.
Furthermore, assume that I have proven $\pi$ secure using a stand-alone simulation-based proof. That is, I have written some proof $\ma... |
There seem to have been defined multiple ciphers using the Keccak sponge as building block / primitive. These seem to have escaped public attention, possibly because they have not been standardized and because current ciphers seem to cover most use cases.
I'd like to know:
Which ones have been defined?
What are the di... |
NIST SP 800-57 Part 1 rev 5 section 5.6.1.1 gives following comparison between different encryption types. For example, it shows that 3TDEA, RSA-2048, ECC224 provides security strength of 112 bits.
Does it mean that with computational power of $2^{112}$, chances of breaking 3TDEA, RSA-2048 and ECC224 are equal? or brea... |
This is from Vitalik Buterin's post.
Here he says
Note that modulo (%) and comparison operators (<, >, ≤, ≥) are NOT
supported, as there is no efficient way to do modulo or comparison
directly in finite cyclic group arithmetic (be thankful for this; if
there was a way to do either one, then elliptic curve cryptography... |
Here is Ariel Gabizon's Blog for the process of converting Arithmetic Circuits into R1CS -
https://electriccoin.co/blog/snark-explain5/
Here, he writes
We assume multiplication gates have exactly two input wires, which we call the left wire and right wire.
We don’t label the wires going from an addition to multiplica... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.