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Clarification on the use of Key block Version ID
For the first time since we migrated to the Key Block we are exchanging keys with third parties,
The keys were all generated by choosing Key Scheme "S".
During export as Key Scheme of ZMK we selected "R".
One of the counterparts is experiencing problems and they believe ... |
In general or in specific examples, how is the group used in an instance of the hidden subgroup problem embedded into a complex Hilbert space in order to apply the quantum fourier transform needed to solve the problem efficiently?
In quantum computing we imagine qubits as unit vectors in a complex Hilbert space $\mathb... |
I need a digital signature scheme with the following characteristics, but I don't know what it's called, so I'm having trouble searching for publications about it. It seems likely that something like it already exists. Could you please help me identify what it's called?
The scheme I need consists of four algorithms:
$... |
By using additive sharing of the private key over the integers, one can obtain a simple threshold RSA signature scheme.
It provides security against a passive adversary.
The dealer chooses random $d_{i}$ from $\mathbb{Z}$ such that the RSA private key $d=\sum_{i=1}^{n} d_{i}\mod \phi(n)$.
In order not to reveal informa... |
Given n voters and p candidates, how can we design a trustless voting algorithm that satisfies the following properties. Each voter can only vote for exactly one candidate.
The algorithm needs to:
Keep all voters' vote private, i.e. only known to the voter itself
Keep the number of votes each candidate receive private... |
In mental poker, we can use ZK-shuffle to deal cards to the players such that the cards are kept private to each player (https://hackmd.io/@nmohnblatt/SJKJfVqzq). Suppose we deal exactly one card to each player, I wonder if there is any way for the players who got the cards with the same number to know this fact withou... |
Say $B$ is a server and $A$ is a client who wants to login to the server, by proving herself to $B$. In challenge-response authentication protocols, $B$ sends challenge to $A$ and $A$ replies with response.
Here, I think all kinds of challenge-response authentication protocols are vulnerable to Man-in-the-Middle attack... |
The spec ( https://github.com/ulid/spec which is not a real standard ) explains that there are 80 random bits in an ULID. UUIDv4 is better from a security aspect, as it has 122 bits for randomness. But UUIDv4 has no monotonic sort order, and that would be very benefical in my actual application.
So how bad would it be ... |
bscrypt is a cache-hard password hashing algorithm/KDF from Steve Thomas (aka Sc00bz/TobTu), who was on the Password Hashing Competition (PHC) panel. He argues it is better than the alternative algorithms on his minimum password hashing parameters page. There are two talks for further information, but it's not thorough... |
we have a concern about a key export.
We completed the migration to Key Block LMK in our environment (with HSM Thales 10K).
Now, we have to exchange keys with third-parties that still use Keys in variant form.
We generated the keys and formed the ZMK using the Key Block standard. To resolve the issue we have to export ... |
According to section 4.2 of Pedersen's verifiable secret sharing, given a secret share $(s_i, t_i)$, it is possible to verify that the secret share is valid by using the commitments $E_j$, for $j=0,\ldots,k-1$, by using the formula
$E(s_i, t_i) = E_0 \cdot E_1^{x_i} \cdots E_{k-1}^{x_i^{k-1}}$, i.e. $g^{s_i}h^{t_i}=g^{... |
I want to test my server application (TLS 1.3) using s_client program from the openssl library and I need to get from the s_client a keyshare in the 1st ClientHello for secp256r1 (it proposes x25519 now). Could you tell me, which command line options in s_client should I use ?
|
Hi I want to implement pedersen commitment ontop of lib sodium
Below is what I am trying to do:
comm1: m1G+r1H
comm2: m2G+r2H
comm3: (m1+m2)G+(r1+r2)H
comm4: comm1+comm2
and comm3 should equals comm4
And here is my code:
unsigned char x[crypto_core_ristretto255_HASHBYTES];
randombytes_buf(x, sizeof x);
unsigned ... |
Hi I am new to lib sodium, may I ask that is it possible to get scalar of ristretto255 from integer/bytes or NTL:zz?
Some thing as follows:
crypto_core_ristretto255_from_bytes(px, x);
crypto_core_ristretto255_from_int(px, x);
crypto_core_ristretto255_from_ntl(px, x);
TIA
|
Given integers $s_1, \dots , s_n$ and target integer $t$, I'm trying to find small integer coefficients $x_1, \dots , x_n$ such that:
$$
t \approx x_1 s_1 + \dots +x_ns_n
$$
Taking inspiration from the Knapsack problem, I was trying to use LLL on the matrix :
$$
B =
\begin{pmatrix}
1 & & & & \\
& 1 & & & \\
& & \ddots... |
LWE schemes are currently being deployed. LWE has no quantum polynomial time algorithms as far as we know.
Despite this what is the consequence if LWE can be broken on a classical computer? Do we have any other alternatives?
|
AFAIK, SuperSingular curves appear to be broken by MOV:
A. J. Menezes, T. Okamoto and S. A. Vanstone, "Reducing elliptic curve logarithms to logarithms in a finite field," in IEEE Transactions on Information Theory, vol. 39, no. 5, pp. 1639-1646, Sept. 1993, doi: 10.1109/18.259647.
I recall that with a big order chos... |
Given $e(a,b)$ as known, can I get the value of $a$ or $b$?
|
Let $N=pq$ be an RSA modulus, that is, $p$ and $q$ are large, distinct primes.
Let $J_{N}=\{y\in\mathbb{Z}^{*}_{N}:(\frac{y}{N})_{J}=1\}$ denote the set of all integers in $\mathbb{Z}^{*}_{N}$ with Jacobi symbol $1$.
The Quadratic Residuosity (QR) problem is to decide whether a given $y\in J_{N}$ is a quadratic residue... |
In asymmetric key encryption, we have 2 functions, encrypt(m,k) and decrypt(m,k), and 2 keys, public_key and private_key.
And it must hold true that decrypt(encrypt(msg, public_key), private_key)) = msg.
Question 1: Are the encrypt(m,k) and decrypt(m,k) functions different, or are they the same function?
Question 2: Mu... |
Homomorphic properties turn out to be very useful, e.g., for achieving secure multiparty
computation.
As a concrete example, homomorphic commitments can be used as a building block for secure election schemes: very roughly, during the voting stage, voters put their votes into homomorphic commitments, and during the ta... |
First of all, I know that I should not be using RSA in 2023, and that I'm better off with Elligator2 + ECIES for a variety of reasons.
However, I am thinking about whether RSA-KEM can be used for PURB-like constructions with long lived public keys. For it to be viable, the RSA ciphertexts should not be distinguishable ... |
I'm trying to understand the security of the Montgomery ladder algorithm in the context of timing side-channel attacks. I'm looking at the algorithm from wikipedia
While I know that the algorithm ensures a constant number of operations in each branch of the if statement, I'm unsure about its overall safety. The Montgom... |
I am looking for guidance on implementing a protocol where a BLS private key is split into 2 out of 3 shares using Shamir's Secret Sharing, and signatures must be obtained without revealing the original message to the other parties.
Here's my current approach:
Alice has a BLS private key. She splits this private key in... |
I hope this question is not too speculative.
Applebaum, Nir and Pinkas have a new paper which has an $n-$party secret sharing scheme with:
reconstruction complexity of $O(n)$ additions
constant share size
sharing complexity of $O(n)$ additions
is a blackbox secret sharing scheme
The shamir scheme has complexity $n \l... |
The ME-600 key generator was developed in the early 1990s for generating truly random one time key streams. That's not exactly World War 1 or 2. I don't know how long it was used, or whether it still is.
Now with quantum computing on the horizon, people are looking at post-quantum cryptography. We also don't yet know... |
I have been given a DES encryption assignment. I was given the Cipher text, the Plain text and the "passphrase". The passphrase consist of a 4 byte hex string. I have studied several different tutorials on you-tube about the workings of DES but I still can't seem to be able to figure out the key. I have tried to ad... |
In short, my question is:
What exactly do people mean when they say that "The more you apply the Rabin-Miller test to a number, the more certain you can be that the number you're testing is prime."?
To clarify what I'm asking, let's look at an example I was working through:
Testing if N = 78007 is prime or not (spoiler... |
I am researching the Xorshift128 PRNG. I am particularly interested in recovering the state given a set of outputs that have the remainder taken with different values.
A common way to take a unsigned 32-bit output from Xorshift128 and produce a value that ranges from 0<=n<50 is to take the remainder of the output and 5... |
In 186-2rsatestvectors.zip/SigVerRSA.rsp
n = bb5784794f27bfab90a19bcc20bb10ac3d1d432d90651dace6235e34560abd733a0c3b693ea3802707c0e22e81603a6e2b82812a0027ece2d974a5a5190df89d636f7ab200849065fe412fe85e41aceb0d68b10cdd07e42ea16184c974f58c10c560aa444f64b41e932ab25355648b510b1feedca780cfb68f11ac9fc98ab15b
p = bda227ead8dc1... |
Looking at https://github.com/tbuktu/libntru/blob/master/src/ntru.h, there are some functions that deal with having multiple public keys with the same private key. I don't believe I need such functionality but it makes me suspect that it might be required. Basically, I want to know if it is OK to reuse the same keypair... |
I don't really know what should be the correct title for this and the community can correct it after reading.
I was the author of PKDSA (Searchable on github).
I have the idea to do it because I feel like shifting from a password based scheme to challenge and respond with digital signature as much as possible might be ... |
I'm still kinda new to Galois theory so I apologize if this question is very obvious to some people.
Basically I'm reading this paper by the NTRU Prime team and in section 2.5 it's explaining how cyclotomic fields should be replaced with prime degree fields with "big Galois group", namely because how structures within ... |
RSA factoring challenge is a famous one and is still not completely solved.
Are there similar challenges for
Discrete log over $\mathbb Z_p^*$?
Discrete log over Elliptic curves?
LWE?
LPN?
|
I designed my TRNG with FPGA. My TRNG has a good entropy performance with a value of 0.99x over several test times. But for the NIST800-22, during several run times, sometimes my sequence passes all the tests, and sometimes it fails one or two tests. (my sequence length is 100.000.000 with the number of run-time for ea... |
First layer of each AES round is the Byte Substitution layer. It is the only nonlinear element of AES. What would happen if this layer was not in the path? And the lack of it would create a problem in the design goals?
|
Can the error in LWE or ringLWE schemes be from $\{0,1\}$? If not why and what is the best attack in this case?
|
I haven't found much info on the internet about the weakness of modes to chosen plaintext attacks, but from what I understand of them, there seem to be some trivial attacks, so I'm a bit confused.
For example, let's encrypt 2 blocks of plaintext with value 0 with CBC:
C0=Ek(P0+IV)=Ek(IV)
C1=Ek(P1+C0)=Ek(Ek(IV))
But the... |
I'm testing my server application (TLS 1.3) using s_client program from the openssl library and I need to force the s_client generating my "random" values in it's ClientHello.
Could you tell me, how can I do it using command line options - where I should point my random sequence to be generated ?
|
Consider a ZKP anonymous credential scheme where each tuple of (x, identity_secret, merkle_root) corresponds to a unique nullifier computed as Hash(x|identity_secret). The prover can use this tuple repeatedly along with proving other statements.
x is designated on a per-session/app basis. And for a specific triple, a u... |
I am reading Section 4.1 (An offline algorithm: SmallDB) of The Algorithmic Foundations of Differential Privacy by Dwork and Roth. I am stuck at the proof of Proposition 4.4, which is about the utility guarantee of the small database mechanism (Algorithm 4 in page 70).
Proposition 4.4. Let $\mathcal{Q}$ be any class o... |
I am reviewing the ZKP course, represented by the university of Berkley (https://zk-learning.org/). In pages 44 of lecture 6 that is attached below (https://zk-learning.org/assets/lecture6.pdf), the instructor explains the Poly-commitment based on Bulletproofs scheme.
I am a little confused that why the verifier comput... |
My question is essentially the same as this one.
The random oracle is a black box that does two things.
Maintain a lookup table for any query that has already been asked.
For all new queries, toss a bunch of coins to obtain a sufficiently long uniformly random bitstring.
As far as I can tell, 1. sounds straightforwar... |
Assume integer factoring, discrete log are classical safe and LWE, McEliece etc are quantum safe. This question is only about SHA and hash families in general on why we need them if we have pkc primitives.
What role does SHA256 or other hash families play? Why are they needed when we have LWE, McEliece etc?
What happ... |
A Diffie Hellman style approach is proposed in https://mathoverflow.net/questions/408757/diffie-hellman-cryptography-based-on-graph-isomorphism but is broken easily.
Two graphs are isomorphic iff there adjacency matrices can be permuted to each other. GI has only quasipolynomial algorithms.
I wonder if there is a toy s... |
I am new to RLWE, would like to ask whether what I am thinking make sense
Suppose I have a message e.g.: x=5
And I have a lattice based encryption scheme, e.g.: BGV
could I encrypt x with BGV by treating x as a polynomial ring with constant coefficient=5, and other coefficient =0?
Thanks
|
Can any encryption scheme that is CCA (Chosen Ciphertext Attack) secure be considered to achieve perfect secrecy?
|
I think it should have APIs for polynomials, FFT and bilinear mapping if KZG commitment scheme is used.
|
Alice wants to send Bob a message. Both have well known public/private EC keys (PA, b, PB, b). Both have well known public keys tied to an identity.
Alice computes a shared secret with Bob (PBa), and uses the x coordinate to tweak her private key, creating a new public/private keypair (PAx, ax).
Alice computes a shar... |
A couple years ago, I devised some primitives for block ciphers and block cipher modes of operation; I was partly inspired by CAESAR. What these designs all had in common is that the encryption/decryption process would produce a bit string $T_i$ for each block and all of these bit strings would be combined together to ... |
I've this requirement to 'derive' a session key from an AES key that is stored inside a HSM. I don't want to mention which HSM since what I intended to do is to make the system HSM neutral.
The initial idea is to use any existing KDF algorithms but since the AES key is in hardware, the KDF is only possible if the HSM s... |
I was wondering if changing modes or primitives could affect security. For example, let's say you have encrypted data with AES-128 with CBC mode and you want to change it to AES-128 GCM, or to ASCON. What I mean by that is that you decrypt the messages then encrypt them again with the new scheme. Does that affect secur... |
In ECDSA, if Alice wants to send a message to Bob, she computes $s=k^{-1}(z+rd_A)$.
I was thinking that the formula could simply be $s=k^{-1}zrd_A$ and the algorithm would work just as well, and the verification would be simpler, because the recipient would just have to calculate $X=s^{-1}zrQ_A$ instead of a sum $X=s^{... |
Update:
In Lipton and Regan's blog, Scott Aaranson and Craig Gidney have commented that the results are not unexpected and also not a deal-breaker in that dealing with this type of noise is already part of the way QC is implemented, including the use of physical measures as well as error correction for making quantum c... |
The NIST Kyber KEM spec. defines an encryption scheme, KYBER.CPAPKE, that's a variant of the so called Lyubashevsky, Peikert, Regev ("LPR") encryption scheme [1]. While LPR encryption is typically defined over subrings of cyclotomic number fields, KYBER.CPAPKE is instantiated over an $R_q$-Module where the base commuta... |
In the paper Dual system encryption: realizing fully secure IBE and HIBE under simple assumption (free PDF), the authors said "there is an apparent paradox in this strategy since it seems that the reduction algorithm could simply answer the challenge ciphertext". In the paper An efficient IBE scheme with tight security... |
Does anyone know what are the family relationships in the paper "How to Explain Zero-Knowledge Protocols to Your Children"
The authors are: Jean-Jacques Quisquater, Myriam Quisquater, Muriel Quisquater, Michaël Quisquater, Louis C. Guillou, Marie Annick Guillou, Gaïd Guillou, Anna Guillou, Gwenolé Guillou, Soazig Guill... |
In Kyber the following estimation is given for a quantum adversary:
Theorem 4. For any quantum adversary $A$ that makes at most $q_{RO}$ many queries to quantum random oracles $H$ and $G$, and at
most $q_D$ many (classical) queries to the decryption oracle, there
exists a quantum adversary $B$ such that
$$\text{Adv}_{... |
Anyone can explaine to me how does the round key in aes256 work please, why is the round key 32 digit while 1 block only have 16 digit? how can 32 digit key XOR 16 digit block? Is it like two digit of round key XOR 1 digit in block?
|
Can anyone explaine how to find the every 15 round key by the 64 hex digit master key of AES 256 please. I will be really greatfull
|
So the problem I'm exploring is basically how to run a paper exam (such as the SAT) in such a way that participants can be sure that their exams were graded fairly, meaning the exam hosts can't change the answers or questions of the exam after the exam is conducted without the examinees finding out.
So we have a test w... |
All the knowledge I have learned about encryption algorithms tells me that the AES encryption algorithm uses three key bit lengths of 128, 192, and 256 to encrypt data, and these three key bit lengths correspond to 10, 12, and 14 rounds of encryption, respectively.
But the question is, why?
Why not 11, 13, 15? Why not ... |
I've generated a key using an HSM Thales PayShield and i have share it with a counterpart. I followed these steps:
i generated key usign KG console command
i use FK to form ZMK from clear components (received by the
counterpart)
i exported key key under ZMK (KE command)
Now, in this particular case the counterpart... |
I have a group of subscribers who are subscribed to a message broker in an IoT setting, let's say to the topic 'sensor/temperature'. Now, I want to create a public/private key pair in such a way that only the subscribers are capable of generating the pair, while the broker remains unaware of it. The publisher will encr... |
The integer factorization decision problem (does integer N have a prime factor = k?) is known to be an NP problem. Analogous to this, can we say that the decision problem for finding the private key of an Elliptic curve (Is r the number of times base point was added to come up with target point) is also in NP, but not ... |
If we use the following notation:
$$C = E(P, K_e)$$
$$P = D(C, K_d)$$
Where:
$$E(), D(), C, P, K_e, K_d$$ are the encryption algorithm, decryption algorithm, ciphertext, plaintext, encryption key and decryption key respectively
The only difference between symmetric and asymmetric encryption is:
$K_e = K_d$ for symmetri... |
I am studying openssl 3.0 (Windows, C++) in order to encrypt data using RSA. More specifically, I need to sign a CertificateVerify server message in TLS 1.3. The questions are:1) how can I define padding mode (PSS) for RSA encryption for this aim ?2) Should I to create EVP_PKEY_CTX* ctx or I need EVP_MD_CTX* mdctx only... |
From the PLONK paper.
Page 23, 6 Constraint System
The constraint system $C = (V, Q)$ is defined as follows.
$V$ is of the form $V = (a, b, c)$, where $a$, $b$, $c \in [m]^n$. We think of $a$, $b$, $c$ as the left, right and output sequence of $C$ respectively.
$Q = (q_L, q_R, q_O, q_M, q_C) \in (\mathbb F^n)^5$
whe... |
In SEAL library, I want to multiply a BFV ciphertext ct with an integer inverse. Here are what I do:
Compute the integer inverse as follows:
uint64_t inverse = invert_mod(pow(2, log_total_item),enc_params_.plain_modulus());
Encode inverse to BFV plaintext using the following code:
Plaintext inverse_pt(to_string... |
My train of thought went, OTP is very secure if key is unknown because I am guessing the original message. AES on the other hand tells me I gave it the wrong key, and if I did I can just switch using another key without having to worry about if the decrypted message using a key that's not the original key was the origi... |
I know it's possible with ECDSA. How bout RSA?
|
I would like to let the receiver has the ability to check the sender's authenticity when he gets the message.
Also, I want to protect the message's confidentiality and integrity.
Should I use aes gcm + hmamc or just aes gcm?
I heard aes gcm provides messages authentication suing Ghash. But ghash is not a mac, so I am c... |
The Pinocchio paper contains a description of the GGPR protocol (Protocol 1), and states that verification requires "8 pairings for the $\alpha$ terms, and 3 for the $\beta$ term". However I can't figure out how to verify the $\beta$ term with 3 pairings, it seems to require 4.
For context, the proof is given as:
$$
( ... |
For security against Chosen Plaintext Attack (CPA), we need randomized algorithms for encryption. But in some schemes (maybe almost all of them) take decryption algorithm deterministic. This procedure occurs in functional encryption, that its security definitions are more complicated than ordinary public encryption, to... |
It's possible to use a hash function as an encipherment scheme if used in counter mode.
Let's suppose I take a 64-bytes (512-bits) seed/key and hash it concatenated with counters, and use it as a encipherment scheme. But the hash function has its digest output size of 32-bytes.
Some hash function such as Blake2 and Bla... |
let's look at the public key in this post as an example: https://crypto.stackexchange.com/a/35105
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCqGKukO1De7zhZj6+H0qtjTkVxwTCpvKe4eCZ0FPqri0cb2JZfXJ/DgYSF6vUpwmJG8wVQZKjeGcjDOL5UlsuusFncCzWBQ7RKNUSesmQRMSGkVb1/3j+skZ6UtW+5u09lHNsj6tQ51s1SPrCBkedbNf0Tp0GbMJDyR4e9T04ZZwIDAQAB
whe... |
Recently a friend of mine showed me a "puzzle" he created with edwards curve ed25519
It is based on adding and multiplying points on the curve
You supply four arguments to the program
The 'public key'
The 'private key'
additional data
static point value
He considers the puzzle as solved if the following 'equation' ap... |
I have been examining the Gazelle paper, which focuses on secure inference protocols. One section constructs a Garbled Circuit using inputs cx, sx, and sy to compute the ReLU function in neural networks. Here, sx represents the server's share of the input and cx stands for the client's share of the input data. The pape... |
I am currently taking a course in university where we are working with a KeePass 2 database file. I am still very new to everything which has to do with encryption.
First I am going to provide the information which was given to me:
A Keepass 2 database file contains different headers, the important ones are the follow... |
I've came across a Stackexchange question about the Chaum-Pedersen Protocol which is based on the generalised schnorr protocol. As I understand it, it uses discrete logs and cyclic groups of prime order q to prove knowledge of a secret value x, which in this scenario is an equality proof for the discrete log.
The paper... |
I have a custom network and I want to implement a symmetric key exchange and key derivation mechanism with ECDH.
I know that I need to use KPP API and ECDH helper functions, but I can't find any code examples in Github or elsewhere (kernel documentation is a bit confusing for me, I'm new to this), so I started to think... |
Ideally, Hashids -: https://pypi.org/project/hashID/ are considered insecure and it is recommended that we should not use them for any sensitive functions. Though, is a HashId considered secure if we pass a very secure random salt to it? Or will it still be vulnerable?
Can someone still guess / reverse engineer the ori... |
Does there exist a semi-prime integer $n$ (e.g., an RSA modulus) such that the order of every element in the multiplicative group modulo $n$ is equal to the order of the full group modulo $n$? If so, would such an integer be more resistant to factorization by Shor’s factorization algorithm (the quantum version) than a ... |
I am trying to wrap my head around Homomorphic encryption, specifically the HEAAN/CKKS scheme. I am reading through the publication, but I am getting stuck on page 11, namely the KeyGen and Enc functions.
My issue in understanding comes from the generation of the public key:
$$
p.k.\leftarrow (b,a)
$$
$$
b \leftarrow-a... |
I am looking for examples post-quantum secure trapdoor functions. Ideally, the inversion knowing the trapdoor should be "simple" in the sense that it can be computed by a circuit in NC^1.
|
If I run cat my.key, I get:
-----BEGIN RSA PRIVATE KEY-----
MIIJKQIBAAKCAgEAu+UkIRXNZrdcnuCLsBsz/HiBcYNoAAAhYi2hISKBxkqX165U...
but if I run openssl rsa -in my.key, I get a different content as:
-----BEGIN PRIVATE KEY-----
MIIJQwIBADANBgkqhkiG9w0BAQEFAASCCS0wggkpAgEAAoICAQC75SQhFc1mt1ye...
why the contents are differ... |
Consider a secure PRG $G:\{0,1\}^\lambda \to \{0,1\}^n$ and a one-way permutation $f:\{0,1\}^{n-\lambda} \to \{0,1\}^{n-\lambda}$. I'm wondering if the following construction $G': \{0,1\}^\lambda \to \{0,1\}^{2n-\lambda}$ is a valid stretch of the PRG output:
Apply $G$ to the input $x \in \{0,1\}^\lambda$ to obtain $y... |
I know how to prove the correct decryption of a (ElGamal) ciphertext.
The above protocol is from the paper: Bootle J, Cerulli A, Chaidos P, et al. Short accountable ring signatures based on DDH[C]//European Symposium on Research in Computer Security. Cham: Springer International Publishing, 2015: 243-265.
But,how to p... |
This question was originally posted in https://ethereum.stackexchange.com/questions/151471/ethereum-signature-as-xml . I post it here aswell because I rarely get any response there.
I am seeking to express an EIP 191 0x45 message signature according to the XML Signature Syntax.
I assume this curve is the correct one: ... |
Consider a function $G:\{0,1\}^*\to\{0,1\}^*$ with output size double it's input size, that is $\forall x\in\{0,1\}^n,\ |G(x)|=\ell(n)=2n$. Assume $G$ is a PRG in the sense of Jonathan Katz and Yehuda Lindell's Introduction to Modern Cryptography (3rd edition); that is meeting the Pseudorandomness criteria:
For any PP... |
I think I understand how asymmetric cryptography works. However I don't really understand why some exchanges use the signature generated by hashing the payload with the private key.
From my understanding, if a public/private key pair is generated for ciphering, the payload is encrypted with the private key by the sende... |
If I have TRNG data as input (A1,A2,B1,B2,C1,C2) - can I xor it to provide more TRNG data A,B,C,D,E,F,G,H ?
A1 = TRNG1
A2 = TRNG2
B1 = TRNG3
B2 = TRNG4
C1 = TRNG5
C2 = TRNG6
A = A1 ⊕ A2
B = B1 ⊕ B2
C = C1 ⊕ C2
D = A2 ⊕ B1
E = B2 ⊕ C1
F = A1 ⊕ B2
G = A2 ⊕ C1
H = B1 ⊕ C2
EDIT:
⊕ is XOR operation, TRNG is true randomnes... |
My problem is about this paper Efficient k-out-of-n oblivious transfer scheme with the ideal communication cost https://www.sciencedirect.com/science/article/pii/S0304397517309143
I don't know what is the "efficient algorithm" in section 3, paragraph 2, the second sentence of this paper.
Could you give me some explanat... |
I am investigating a PRNG which fails some of NIST tests (FFT, ApproximateEntropy and Serial). If such a generator is used in cryptography for any purpose, what consequences can it has? How this vulnerability affects its safety? What is possible attack?
I want to discuss implications.
|
I'm trying to extract a private key from a .PFX file to a .PEM file format. I was able to do it using Aes128Cbc in either .NET or OpenSSL:
.NET:
PbeParameters pbeParams = new PbeParameters(PbeEncryptionAlgorithm.Aes128Cbc, HashAlgorithmName.SHA256, 1);
byte[] privateKey = rsaPrivateKey.ExportEncryptedPkcs8PrivateKey("... |
NIST 800-90C defines 3 classes of random bit generation (RBG) constructions: RBG1, RBG2 and RBG3. All constructions must include a DRBG from NIST SP 800-90A. The particular construction in question is RBG3, which is "designed to provide output with a security strength equal to the requested length of its output by prod... |
I am trying to test my server program which implements TLS 1.3 connection - it should establish TLS 1.3 connection.
My server uses a self-signed certificate, created in openssl.
I am using Firefox v.112 as the client to connect and getting an error - "SSL_ERROR_RX_MALFORMED_HELLO_RETRY_REQUEST".
How can I know the spec... |
I have pairs of files A and B both of arbitrary size and contents (for any pair of files, A could be significantly larger than B or vice versa). I want to be able to 'encrypt' A in such a way that I can distribute it openly, but so that only people already in possession of the entirety of B can access any part of A reg... |
I do not know why the intermediate value (for example, W5, W6) should be encrypted??
I think the encryption (random value) only needs in the input process (e.g. w1, w2, w3, w4).
|
U= 115792089237316195423570985008687907852598652813156864395638497411212089444244
a = 20412485227
E1 = EllipticCurve(GF(p), [0,1]) with order U
E11 = EllipticCurve(GF(p), [0,1]) with order a
Formula from Coords on E1 to Coords on E11 is
Q11 = (U/a) * (x,y) (x,y) on E1
But, what is the reverse formula from Coo... |
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