instruction stringlengths 32 27.2k |
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The XOR operation is an important part of most of the existing end-to-end authentication protocols. Will it be part of the post-quantum authentication protocols?.
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How can $n$ peers compute
$$\frac{1 + a_1 \times \dots \times a_n}{b_1 \times \dots \times b_n}$$
such that the pair of values $a_i$ and $b_i$ remains secret to the $i$-th peer?
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I came across DES-EDE3-CBC and a quick search didn't yield a clear explanation of what it is.
Clearly, DES is the Data Encryption Standard and CBC is the Cipher Block Chaining mode.
EDE is probably Encrypt-Decrypt-Encrypt and maybe the 3 means that 3 distinct keys are used?
It's somewhat mentioned in this question but ... |
Bleichenbacher’s ’06 RSA signature forgery targets incorrect PKCS1 v1.5 implementations where padding checks are omitted and RSA keys with e = 3 are used.
As per the answer to a related question, the attack has the following additional assumption
… with the assumption that the lsbit of the hash is a 1 (or more gener... |
I want to create a SHA256 hasher in Circom so I can validate that a person knows the pre-image of a SHA256 hash without revealing the pre-image. This is my current code but it doesn't work:
include "/node_modules/circomlib/circuits/sha256/sha256.circom"
template SHAHasher(nBits) {
signal input bits[nBits];
signal ... |
Are real-or-random(rr) model and LR-model are equivalent?
In the definition of ciphertext indistinguishability, LR-model is used. However I think rr model and LR model are somewhat equivalent.
Here is what I really want to know:
When proving some cryptosystem(ex. ElGamal under DDH) are IND-CPA secure, can we just use r... |
What are the possible assumptions that have been used or can be used for designing the homomorphic Collision Resistant Hash function (CRHF)? I know Short Integer Solution (SIS) is one of the assumptions used for designing homomorphic CRHF.
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As far as understand AES takes 16 bytes, shuffles them and replaces every of the 256 bits via XOR.
Then the same procedure applies to the next 16 bytes, and then again - until the entire file is encrypted.
What if I just randomly shuffle numbers from 0 to 15, and also randomly write zeros and ones, 256 in total, and t... |
I am reading about the Ring signature. However, I do not understand the verification process of this signature. Could you provide me a complete numerical example showing the signature creation and verification process? In case of RSA, there are many numerical example are available but I have found none for Ring Signatu... |
NIST SP800-56C r2 added Section 5.3 which specifically addresses using a single Extract step followed by m Expand steps using the same key-derivation-key produced in the Extract step.
This is a very common widely-deployed scenario (ex. processing master-key in Extract, then generating multiple derived keys with Expand... |
I have seen different protocols in field or ring, I used to think ring is a special field when 2^k. But when I read the paper later, I doubted my understanding.
|
I have read SPDZ family protocol, the domain of the spdz_1 in 2012 is $\mathbb F_{p^k}$. Later mascot'16 supports both $\mathbb F_p$ and $\mathbb F_{2^k}$, where $p=2^k+u$.
I want to know the difference between the protocol in $\mathbb F_p$ and in $\mathbb F_{2^k}$. The reason maybe that spdz_1 use SHE, which only supp... |
Context
I am implementing LSAG in python because I do not find a non-obviously insecure implementation. I am not a cryptographer myself, thus simplicity is key.
The famous Linkable Spontaneous Anonymous Group Signature for Ad Hoc Groups paper states these algorithm parameters:
Parameters:
group G of prime order q
hash... |
I am currently working on password manager. So far I used one encrypted database file to store all the passwords and then decrypted it at runtime with a derived user-entered master password. All log-in data was then loaded into memory to present it in a user interface:
I am searching for a more secure way to especiall... |
I'm currently working on a webapp in which I'd like all nearly all user data to be encrypted, but accessible by multiple users (ie a doc encrypted should be decrypt-able by parties A, B, C, all independently). Is there any way to achieve this?
One issue I realized is that it would be nearly impossible based on my knowl... |
Given an encrypted (RSA) message and it's original plain text, is there a way to prove that the plain text belongs to the encrypted message ?
|
Wouter Castryck and Thomas Decru recently broke SIDH.
From the abstract:
We present an efficient key recovery attack on the Supersingular
Isogeny Diffie-Hellman protocol (SIDH), based on a "glue-and-split"
theorem due to Kani.
The referenced Kani work is:
Ernst Kani, The number of curves of genus two with elliptic di... |
Is there a way to encrypt a file with 2 (or more) keys and then access it with only 1?
Scenario:
Bob and Alice have a tight memory and can only remember ONE key.
Bob and Alice encrypt a file with their keys.
Bob goes in coma and Alice wants to access the file, but has only one key.
Is there an algorithm that solves t... |
I'm mainly trying to verify large file chunks which are encrypted each alone with a different key/salt/nonce for each chunk then appended to the whole file in the end to form 1 file.
One thing I wanted to implement was the principle of not outputting plain data of any chunk to the user unless every chunk of the file au... |
I am trying to make a byte-serial implementation of the AES 128-Bit in ECB-mode for my studies.
I understand the "normal" (word-parallel) implementation of AES and the way of Eli Biham (bit-serial). Both extremes of the representation variants, namely bit-serial and word-parallel, were examined, but what is about byte-... |
According to this webpage:
The process of encoding a private key into WIF format is as follows.
Raw private keys are simply large numbers, which are represented as
bytes. WIF format adds a prefix byte (0x80 for mainnet and 0xef for
testnet) so that almost all Bitcoin private keys begin with ‘5’ or a
‘K’ on mainnet. Ne... |
What would be a way to prove that both you and I know the same dictionary word? If we both hashed the word, then we could compare the hashes, but anyone who saw the hash could find the original word by hashing all the words in the dictionary. What would be a better way?
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Avalanche is one of the characteristics of S-Box or SP network(S and P boxes are used together).Is it possible for the permutation module, when tested alone, to show avalanche effect.? reference SP network in block ciphers
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For generator point $G$ in the secp256k1 curve, I want to find a value $k$ such that:
$$h\equiv(k\,G)_X\,(k-d)\pmod n$$
where $n$ is the group order, and $(k\,G)_X$ indicates the x-coordinate (mod n) of the resulting point after the multiplication by $k$. Assume $h$ and $d$ are fixed scalar values that I've been given.... |
HKDF-Extract is defined in RFC 5869 as
HKDF-Extract(salt, IKM) -> PRK
Options:
Hash a hash function; HashLen denotes the length of the
hash function output in octets
Inputs:
salt optional salt value (a non-secret random value);
if not provided, it is set to a ... |
In RSA, signing the hash of a message is doing the operation $h^{d} \bmod N$ where $d$ is the private key.
Given that the size of $d$ is usually 2048 bits and $h$ is a quite big number, the exponentiation will take too much time.
For example in python raising a number of 9 digits to the power of a number of 8 digits to... |
I am currently studying and implementing ECC algorithms but I encountered a problem. I want to use Secp521r1 for generating a shared key and encrypting with ECIES using AES256 but AES-256 requires a 256-bit key while the shared key is 521-bits. How can I use a 521-bit shared key for encrypting with ECIES AES-256?
Shoul... |
I am new to Oblivious Transfer (OT) and am having trouble finding a definitive answer regarding if/when/how baseOTs can be reused in a computation when using OT-extension (for passive security only).
Say two parties are running a secure function evaluation (SFE) protocol and need to use multiple rounds of oblivious tra... |
I am new to ECC but I was wondering,
If there is a situation where instead of the ciphertext being falsified, the sent MAC was tampered. How does the receiver verify that the ciphertext is still correct? How can the receiver verify that only MAC is tampered with? How is it possible to know whether the sent MAC or Ciphe... |
In [1], the authors state:
[...] observe that unlike [32] the initial OT phase in Protocol 52 is
completely independent of the actual inputs of the parties. Thus, the
parties can perform the initial OT phase before their inputs are
determined.
where “initial OT phase” refers to the base OT phase. In a follow-up/exten... |
I've been trying to learn about attacks on LPN ($n$-bit secret, noise rate $\eta$), and have found several allusions to a brute force algorithm that runs in time exponential in $n$ and requires a linear number of samples in $n$. For example, the third slide of this deck or the original BKW paper. That said, I have not... |
Given a plaintext of length 20 over the latin alphabet {A, B, . . . , Z} and the RSA key (n, e) with n = 77. Find a way to break up the plaintext into as little as possible blocks of information, each of which can be encrypted by the RSA algorithm using the given key.
My question is,
What are the possibilities for a p... |
I am creating an internal application that will be used to generate and manage self-signed certificates and certificate authorities. Its primary use will be for generating certificates used in SSL decryption by my clients' firewalls.
My goal is to have a deterministic RNG that could be fed into either RSA key generatio... |
Let's say we have a certain amount of LSB bits of P and Q and we want to fully reconstruct them given N=P*Q. I know this problem was studied in literature by Coppersmith and that Lattice methods are pretty efficient but I would like a numerical / sagemath code example.
If we have for example
N=23767*17191=408578497
and... |
Given a CSPRNG (arc4random, using ChaCha20 keystream), one want to use rejection sampling to get random number on a smaller range avoiding modulo bias (arc4random_uniform()).
OpenBSD's arc4random_uniform() implementation draws a 32bits value and tests its fitness, rejecting values that don't fit.
It's not the only poss... |
I am learning about stream ciphers, which apparently are unpopular. I just want to have a better idea of some basic algorithms that are in use or were in use till recently.
I checked:
the OTP: Apparently great but unpractical
Linear Congruent Generator: insecure
LFSR: not sure yet but it appears insecure
Can you sugg... |
Background:
In Wikipedia (bilinear map definition), a condition listed as the following:
For any $\lambda \in F, {\displaystyle B(\lambda v,w)=B(v,\lambda w)=\lambda B(v,w)}$
In a math.stackexchange post, i saw this comment:
which defines bilinearity in the same way as the Wikipedia link. So I assume, the above defini... |
As far as I understand it, TLS creates a tunnel or channel or secure connection between the parties right? Where everything is protected? But hypothetically if the network gets breached, would the raw data/message sent from one client to another through a central server be readable? If someone gets inside the tunnel so... |
A vector commitment scheme is a scheme (dough!) that allows a prover to prove that $v_i$ is a component of a vector $v$ without revealing any other information about $v$ . (So the prover commits to $v$ and then proves that $v_i$ is one of it's components).
To the best of my knowledge, current vector commitment schemes ... |
Which algorithm is more crypto-resistant: AES or Kuznechik (GOST R 34.12-2015)?
|
I am using zkSNARK to prove knowledge of preimage for SHA256. However, the library used only supports field operations (such as add and multiply), and it compiles down to arithmetic circuits. Thus, bitwise operations prevalent in SHA256 have to be simulated using field operations. How can they be simulated, say, left s... |
In the zero knowledge definition of the Groth16 scheme (https://eprint.iacr.org/2016/260.pdf) [Section 2.2], why would the simulator be allowed a trap-door in set up? The trap-door information contains the toxic waste that should be destroyed by the set up. In another word, if the simulator (a.k.a modeling a passive at... |
Traditionally, hash functions are single-threaded, and have the 'Init-Update-Final' API style. This is true of MD5, SHA-1/2/3, BLAKE2, to name a few.
However, there have been proposal of parallel hash functions, and tree-hashing. BLAKE3 and KangarooTwelve are among these.
If we continue to use the IUF API, then data-av... |
I am trying to find the flag from an RSA ciphertext, I am able to get the factors from factordb.com but the given e is not coprime with phi(n). One weird thing that I observed is that n and cipher_int has 10264 digits (looks like an integer). I am very new to crypto, Any ideas on how I can solve this?
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This is a simplified version of a question I made long ago, that never got an accepted answer.
It's given $N$ of $n=2048$ bit, assumed hard to factor, which two prime factors each are $\equiv2\pmod3$, so that the public exponent $e=3$ is usable. It's also given $C\in[0,N)$, known to have been obtained as $C=M^3\bmod N$... |
May someone please explain what the notations in the image means?
In general, for a modulus $q$, what does the $+$ in here $\bmod^+ q$ indicate? What does the $\pm$ in here $\bmod^\pm q$ mean?
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Let $\mathbb{G}_1$, $\mathbb{G}_2$, $\mathbb{G}_T$ stand for three groups of the same large prime order $r$. I invented a pairing $e\!: \mathbb{G}_1 \times \mathbb{G}_2 \to \mathbb{G}_T$ (with embedding degree $k \in \mathbb{N}$) such that $$
\mathbb{G}_1 \subset J(\mathbb{F}_p), \qquad \mathbb{G}_2 \subset E(\mathbb{F... |
Please see the image below which represents an algebraic definition of the Dolev Yao Closure. From reading around, it appears this is BAN logic and that the lines mean "If you believe the above statement is true, then you must believe the lower statement is also true."
Is this accurate and why do the statements appear ... |
Consider the Schnorr identification protocol. Let $x$ be secret key, $u$ be public key, $r(\xleftarrow{$} \mathbb{Z}_q )$ be a random number with $u_r=g^r$ the commitment that prover uses at first round, and $c(\xleftarrow{$} C)$ be the challenge that verifier challenges to the prover at second round.
At the last roun... |
I'd like to encrypt a file with AES256 and provide my own 32-bytes for the encryption, rather than having GPG derive it from the passphrase.
I could not find such option, but I'm thinking about a possible workaround.
Per this message:
https://lists.gnupg.org/pipermail/gnupg-devel/2018-June/033795.html
The other use of... |
In the BGN-like LWE cryptosystem, section $2.2$, we sample a $m \times m$ trapdoor matrix $T$ that is full rank such that $TA = 0 \pmod q$.
Suppose that $q$ is prime so we are in a finite field: if $T$ is full rank, the nullspace of $T$ is trivial, and $A = 0$?
In particular, $T$ can have rank at most $m-n$?
|
There is a lot of "retail investor" hype implying a zk revolution in the future where we have circuits for common instruction sets and many software backends are zk-proven.
I'm wondering, are there any fundamental results (e.g. impossibility theorems, bounds) like, proving key must be x times the size of the unproven p... |
I'm using OpenSSL 1.0.2 and FOM 2.16 and am trying to figure out a way to draw entropy from Intel (RDRAND/RDSEED) if it's available, and from the Linux OS (/dev/random or /dev/urandom) if it's not. If I build OpenSSL with
--with-rand-seed=rdcpu,os
it tries to get entropy first from the Linux OS. I need it to try RDRA... |
Quoting Ristretto255 for the PHP Community,
Ristretto255 is Ristretto defined over Curve25519, which allows cryptographers to extend the Ed25519 signature scheme to support complex zero-knowledge proof protocols without having to deal with the cofactor.
(The cofactor in Ed25519 is what caused the multi-spend vulnerabi... |
Given n nodes(miners/validators),
Every unspent transaction output is broadcasted to all n nodes.
Each node will select a batch of transactions and add it to their
block. The specific mechanism of how they select transactions will
be dependent on each node’s source code.
A node gets randomly selected to add a block to... |
I have been working on signcryption scheme and its security proof. I want to compute the efficiency in terms of number of scalar multiplication operation, number of exponential operations, and number of bilinear pairing operation. I am comparing it with other schemes as well. I think I am missing out some information r... |
I am making a password manager , I am new to cryptography, so , can someone tell me if this can be a good solution?
1- the user inputs the email/password
2- all the payload gets encrypted with aes@256bit and saved on a public blockchain
It should work right?
and one more thing: as you know storing data on the blockchai... |
I came across an interesting challenge recently. I need to find x such as :
$s=n^x \mod m$
We suppose we have $s, n$ and $m$. The modulus $m$ is prime and $n$ is a primitive root modulo $m$.
The interesting property is that $m$ can be written as $m=a^2+b^2+c^2+d^2$ where $a,b,c,d$ are integers.
Given the decomposition ... |
I have read the Bitcoin paper and there is one statement that I would like to know if it is really proven ir not:
The only way to confirm the absence of a transaction is to be aware of
all transactions
The point is that if this statement is false, maybe there is a mechanism to solve the double-spending problem withou... |
I found an algorithm described in my old math notes that I wanted to dive into further, but the name I noted is apparently completely wrong ("Bolson Adding"), so now I am trying to find the actual name of it.
You have an array of digits 0-9 and add them up in pairs, starting with first+second, then third+fourth, etc., ... |
I'm new to modular arithmetic but it still is something that I think is pure mathematics that I don't get.
I have this problem 3 * d ≡ 1 mod 13. So I need to find the d which is the inverse of 3.
I did find a solution that I understand:
3 * d ≡ 1 mod 13
Which can be written
3^(13-2) % 13 = 9 or pow(3, 13-2, 13) = 9
So... |
This is a rather simple question but I've been unable to find a proper answer for this online.
When defining an asymmetric (public key) algorithm is the one-way trap-door function usage referring to the encryption/decryption function or the key generation process or perhaps both?
I believe that the one-way function is ... |
I have tried to answer this question for quite some time now. But a complete intuitive understanding still eludes me:
suggested a new implementation for AES:
The byte substitution step will be replaced by the function:
$$s(b_0b_1b_2b_3b_4b_5b_6b_7)\,=\,b_7b_0b_1b_2b_3b_4b_5b_6$$
( a cyclic shift of one bit to the right... |
With the appearance of cryptocurrencies several applications of ZK proofs were envisioned. However, to the best of my knowledge, all of these are proofs of knowledge.
My question is: are there any real-world applications (in contrast to applications within cryptography) of ZK proofs without the proof of knowledge prope... |
Based on many suggestions I have seen around, this, that.etc. Best practice says to keep the root CA offline for very understandable reasons.
But how can it be truly offline? Doesn't the root ca have a list of int cas that it trusts. so therefore when a user goes to a website the chain has to be completed. So there is ... |
I’ve read a lot of articles and a lot of questions here to understand how the encryption is done in garbled circuits. As I understand double encryption is to encrypt the gates and the truth table. The thing I wonder is how do we do that double encryption. Which method is used to generate keys?
This is what I’m talking ... |
My question is:
Alice signs messages using RSA with a public key $(e,N)$ and a private key $d$. Alice chooses $d$ in the range $N^{0.25} < d < N^{0.5}$.
What is the time needed for Alice to calculate the signature $S = m^d \bmod N$?
My answer is: Alice chooses $e$ so that $d$ is in the range $N^ {0.25} < d < N^ {0.5}$.... |
Recently I across this cryptographic library for Oblivious Transfers. In the README file I saw many OT flavors that I haven't seen before, more specifically the following :
General OT
Correlated OT
Global correlated OT
Sender random OT
Receiver random OT
Could anyone help me clarify their meaning? Thanks in advance f... |
I’m having difficulty calculating the false positive error probability of matching a prefix of a hash that was truncated to m bits.
Say I have string S1 that produces a SHA256 hash H1. I then save the the first 64 bits of H1, call it prefix P1 to a database.
I have another string S2 that produces a SHA256 hash H2, and ... |
This is not a formal but intuitive concept of one-wayness. The intuition is that if you have a combinatorial object that requires $n$ bits to describe. A one way operation introduces noise in random bit locations such that $\epsilon n$ bits are modified. Then only exponential time algorithm can invert the function. Are... |
I have been reading the book "Serious Cryptography" by Aumasson to begin learning about Cryptography. There was a part where the author suggested how encryption using permutation should have these properties to be secured
It should be a
permutation, which is a rearrangement of the letters A to Z, such that
each lette... |
I want to check if some pubkey belongs to twisted edwards25519 (I guess this is used for ed25519 ?) The problem is that I have in theory some valid pubkeys like:
hash_hex = "3afe3342f7192e52e25ebc07ec77c22a8f2d1ba4ead93be774f5e4db918d82a0"
or
hash_hex = "fd739be0e59c072096693b83f67fb2a7fd4e4b487e040c5b128ff602504e6c72"... |
I am moving from RSA to ECC for my application.
Looking at these posts 1
2
3, they all suggest that Alice generates a temporary (ephemeral) ECC keypair eKP to send a message to Bob.
The sessionkey sK is then generated at Alice' side as (privateKey eKP * publicKeyBob).
The publicKey of eKP is transmitted along with the ... |
I'm currently debating whether to revert to a non-committing AEAD (ChaCha20-Poly1305) instead of a committing AEAD based on Encrypt-then-MAC (XChaCha20-BLAKE2b) for stream encryption. Borg backup made the switch, and non-committing AEADs have several advantages:
Standardised
Generally faster
Less overhead due to short... |
I mean this has certainly been implemented by some scummy PRNG developers, which thought of the economics behind it (especially in the casino and similar businesses). So it might be even legal in some cases, but this not Law StackExchange ;-)
Yes, I am aware that PRNG have a period and hence are practically determinist... |
With public-key cryptography, I know Alice can "seal" a message that only Bob can open. But in that case, Alice knows the message that she is sealing.
What if Alice wants to seal a random number which she doesn't know? Could she seal it such that only Bob can determine it, not Alice?
Here, more specifically, is the kin... |
In the CTR mode, a nonce, a counter value and the key are needed to form the input of the PRF. However, the Deterministic counter mentioned in Dan Boneh's slides (https://crypto.stanford.edu/~dabo/courses/OnlineCrypto/slides/04-using-block-v2-annotated.pdf, pp. 20), does not have the nonce. It only uses the key and the... |
Can Shamir's secret sharing work on any size of key?
|
I have to encrypt data (files) of client on server side and only the client can read theses files (admin can't see name and content of file).
To resolve this, I have the idea to just use something client have and the admin doesn't, his password to generate a cipher key, this idea is simple.
But I have a constraint for ... |
I have just learnt about Diffie-Hellman and AES. However, I cannot seem to understand how they link.
My initial idea was that Diffie-hellman is used to transfer a key for AES decryption. After further research, I understand that AES uses the key that is produced by the Diffie-Hellman.
I don't understand how it uses it ... |
Given that:
$$ SD\bigg( (r, \langle r, s \rangle),(r, b) \bigg) < \mathrm{negl}(n)$$
where $SD$ stands for statistical distance, $r$ is random uniform in $\{0,1\}^n$, $s$ is random uniform in $S \subseteq \{0,1\}^n$ and $b$ is a uniformly distributed bit.
It seems intuitive that, given a collision resistant hash functi... |
General
My goal is to encrypt some strings and store them in a database.
I am using RSA OAEP in Go (Golang):
rsa.EncryptOAEP(sha256.New(), rng, rsaPublickey, plaintext, nil)
rsa.DecryptOAEP(sha256.New(), rng, rsaPrivatekey, ciphertext, nil)
I generated a public/private key pair with 4096 bits.
My understanding of RSA ... |
In cryptography output sequences of stream ciphers are binary valued (or more generally finite field valued). However mathematically sequences over real and complex variables can also be generated by stream ciphers utilising feedback shift registers. We can also convert a binary output sequence $w(k)$ of a stream ciphe... |
Short Version: SHA-256 uses addition alongside a variety of bit-wise operations. What's up with that?
I was reading a description of how SHA-256 worked and it included a description of the various internal operations that take place on the blocks of bits while the algorithm does its work.
Most of them made sense to me ... |
The question is fairly simple and is actually stated in the title although I will elaborate a bit further on it. Also, I'm not really sure if this belongs here or it partly belongs to cstheory.stackexchange.com.
Currently I'm trying to understand ZKP as a class of problems. I have read that IP=PSPACE and that ZKP exist... |
I was curious which of Groth16, Halo2, Bulletproofs, etc have statistical vs computational zero knowledge guarantees. This would inform post-quantum zero knowledge as well, since I imagine that past statistical zero knowledge systems will not be de-anonymized, but past computational zk may. (Note that I am not concerne... |
I want to know if there is a multisignature scheme that allows the merging of two multisignatures for the same data but by two different sets of users, and without knowing the corresponding private keys. The goal is to obtain a single multisig that has the same size than the two multisigs it originates from.
This would... |
I plan to use it locally on mobile devices. These seems to do not offer computational power as good as on a server.
So what could be a secure argon2id parameters that run around 1s since offline apps should also be friendly too?
|
The question is mainly stated in the title, sorry for it being a bit small of a question. I was reading about ZK proofs and I was wondering what do we know about their limits only their properties. Do we have any impossibility theorems or any assumptions that we strongly believe that hold? Thanks in advance for your ti... |
I'm implementing a searchable symmetric encryption scheme, developed by others, for my own personal enrichment. The original research is located at the link: https://eprint.iacr.org/2013/169. I'm using the BigInteger class in Java to perform the group operations. The scheme splits the exponentiation between the cli... |
Please, can any extensively explain the importance of super encryption in relation to attacks experienced by single standard algorithms
|
This question is someway correlated to Breaking RSA with P,Q LSB bits but more specific.
I would like to use LLL to fully reconstruct P,Q given some LSB bits of P and Q in an arbitrary base B.
Let's take RSA 100 and B=12 as example and sagemath as calculator:
# p,q solutions in base 10
# p = 379752279369436739228088727... |
Let $e:G_1\times G_2\to G_t$ be an asymmetric bilinear pairing, $g_1$ be a generator of $G_1$ and $g_2$ be a generator of $G_2$. Can we compute $g_2^t$ from $g_1^t$ when $t$ is unknown?
|
Consider this scenario:
A signs a message to B using A's private key. A then encrypts the signed message with B's public key. A sends both plaintext and encrypted message to B so that B can verify.
B receives the messages from A. B decrypts the signed message using B's private key and verifies that the plaintext mess... |
From what I know SSS creates a polynomial with a0 = secret key and interpolates it on recovery using k coeffs. if a0 is a number, can SSS fully recover keys with 0 bytes in front of them?
Example, If I make shards for 00d3e4bb740636a65d31a8b00793187c will I get d3e4bb740636a65d31a8b00793187c upon reconstruction or 00d3... |
I'm primarily a mathematicians dipping my toes into cryptography, and I have often seen/heard cryptographers use the heuristic that a uniformly random sample $a$ from $(\mathbb{Z} / N \mathbb{Z})^\times$ will be "large", or that $a \approx N$, without referring to a specific result.
I want to make sure I understand the... |
I'm trying to create the digital signature by using these parameters and RSA algorithm:
p = 645353605880701501120167331073
q = 350784310265709643169455170929
e = 19
message = "G’day mate! As we are using a publicly available free WiFi network, our communication may be intercepted by cyber attackers. Therefore, we need... |
I'm aware that the difference between the NaCL sign keys vs the box keys is that the secret key that comes from the NaCL box keypair is the 32 bit secret key + 32 bit public key.
So I decided to use the tweetnacl.js library to create a signing key and use the box functions to encrypt and decrypt data.
I used the nacl.s... |
Do I understand correctly that the textbook Rabin encryption scheme, where there is no random padding (as is also required in RSA for it to be CPA secure), is not CPA secure? (it is deterministic without such padding), or am I missing something?
My confusion arises from the wikipedia article which states that it is CPA... |
I was wondering, if the output of following type of ChaCha + HMAC scheme is indistinguishable from randomness:
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
from cryptography.hazmat.primitives import hashes, hmac
def chachaHMAC(key, nonce, data): #Do not reuse nonce!!!
#Make differen... |
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