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I understand that domain separation in hashing is important, but I'd like to understand more clearly why and what are the risks involved.
What is the theoretical justification for requiring domain separation?
What are examples of schemes/protocols that can be broken if domain separation is not used?
How can one evalua... |
Let $H(h,k)$ be the expected entropy of some random oracle $X:\left\{0,1\right\}^h \to \left\{0,1\right\}^k$, where $h$ does not necessarily equal $k$.
Then, is it true that $\lim\limits_{h\to\infty}H(h,k) = k$ ? (for constant $k$)
If so, is the above still true if $h = 2k$? In other words, does $\lim\limits_{h\to\inf... |
Bilinear Pairings are widely used in many new schemes like Group Signature and Aggregate Signature. The problem is whether it is post-quantum secure. In other words, does Bilinear Diffie-Hellman intractability assumption stand against a quantum computer?
With a quantum computer, Shor's Algorithm solves Prime Factorizat... |
We have 2 ciphertexts, one encrypted using Paillier and another encrypted under Elgamal encryption schemes. Is there a way to design ZK-proof to prove equality of the underlying plaintexts of these 2 ciphertexts.
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Some time ago I had a question here about WinRAR security and probably the most common recommendation I came across was to use Veracrypt.
Veracrypt uses XTS, but according to others, XTS encryption is unnecessarily complicated and does not provide such protection to be considered secure enough. (see Thomas Ptacek; Erin... |
Under which conditions is it secure to publish an encryption of the secret key $s$ under itself in terms of an $RLWE_s(s)$ ciphertext? Because for some schemes this is (repeatedly) used in bootstrapping or key switching, it seems to be secure (or at least it is assumed to be so).
On the other hand, if multiple encrypti... |
I want to prove that the DSA signature scheme is EUF-CMA secure in the random oracle model, if the discrete logarithm problem is hard. I know it can be proved by the following two parts:
Discrete logarithm problem is hard $\Rightarrow$ DSA identification scheme is UI-PA security
DSA identification scheme is UI-PA sec... |
I'm thinking about storing packed integers $(x_1,x_2,...,x_k)$ into a single ciphertext slot using the Chinese Remainder Theorem (CRT). However, in order for the CRT to work, the plaintext modulus would have to be a product of prime values (the same prime values used in the CRT). So I ask, does the plaintext modulus ha... |
Considering that I am writing a circuit that will take age as input and return true or false.
For this ZKP system, I guess I don't need a separate prover circuit and verifier circuit.
Consider that I am writing a circuit that will take age as input and generate a proof. Now I will write another circuit for a verifier t... |
The shape of the edwards curve is equal to $a x^2 + b y^2 = d x^2 y^2 + 1$ in $\mathbb{Z}_p$. Is there a way to know $p$ when we know the five points on the edwards curve without knowing $a, b, d, p,$ and generator $G$?
I tried to find p by using the five points given to me by concatenating the relationship $a x^2 ... |
I want to hash my signature of JWT using public & private key, since we are using ES-256 algorithm in JWT. But the problem is that I have both the keys in JSON & .PEM format, so how can I do it in one openssl command? below is the shell script code which I am using to hash the signature:
SIGNATURE=$(echo -n "$DATA" | o... |
Can you explain the mathematical details of Grover's algorithm for children?
|
I am building the Threshold Signature Scheme (TSS) based wallet. I would like to run the each party's node separately with different host. And these nodes should be able to send the messages through the secured and authenticated channel to the other partie's nodes. So what channel protocol is prefered to used. Can i us... |
Is there a known feasible method for determining an unknown public key from a Diffie Helman shared secret and the other public/private key pair?
This would be rarely useful, but I am curious if the DH operation is 'invertible' given the derived secret and private/public key of one party.
So if the shared secret (which ... |
This question is about adding new data with different proportions to a dataset with equal proportions for each type of data, and determining at what point the added data can be distinguished.
For example, in a hospital with doctors, nurses, cleaners, and security personnel, with proportions of [0.5, 0.2, 0.2, 0.1], the... |
I am currently studying the Double Ratchet Algorithm from Signal (link to the documentation). I stepped over a security issue which I was not able to find that it was mentioned anywhere.
I assume that an attacker is able to delay messages at the public channel. Let's say Alice and Bob are having a conversation via doub... |
If we know the value of G*n, the value of n, and the value of p in Zp, is there a way to find out G?
I tried the code below on sage but the value was different from the original G.
# we know nG = (x, y)
Gx = inverse_mod(n, p)*nG[0] % p
Gy = inverse_mod(n, p)*nG[1] % p
G = (Gx, Gy)
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I am learning Elliptic Curve cryptography, I have been working on an example from a book:
I don't fully understand the line where the slope is calculated, specifically how 2^(-1) * 9= 13 mod 17? I saw a post here that says to get the inverse with the Extended Euclidean algorithm.
I just don't see what 2^(-1) is the i... |
sbverify needs a certificate to verify digital signatures. I wonder why it's needed, since the signer certificate is already included in the digital signature itself ?
|
I have a program in Python to do the ECDH with the NIST P-256 curve. The program is seemingly working, ie I get the same private key pair at the end. But I want to make sure it's not a coincidence in my code, and that my double-and-add algorithm is working correctly.
TLDR: Is there a strong curve that gives all the det... |
I understand the only multilinear maps used in cryptography are bilinear maps, and higher arity multilinear maps are not "known."
Why does the composition of bilinear maps not yield usable higher-arity maps?
I thought the primary feature of multilinear maps in cryptography is simply their multilinearity along with non-... |
I implemented below algorithm in hardware and it works fine with first point addition.
However, when I continue to perform back-to-back addition, I got the wrong result.
The part that I'm not sure here is,
The original calculated X3 and Y3 are still in Jacobian coordinate and I do not want to convert them back to aff... |
When trying to implement ElGamal Public Key Encryption using Hyperelliptic Curves, one needs to map the message that will be encrypted to a valid Divisor (in my case in the Mumford representation, which is the most common).
I have not found any specific methods similar to Koblitz encodings in ECC. Are there any methods... |
What would be the method of choice to compute the private key from the public key on a baby analog of secp256k1, say with $p$ and $n$ 144-bit?
What would be the pros and cons of Pollard's rho and Pollard's kangaroo ?
How can the special properties of a Koblitz curve be put to use?
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Our device comes with a device certificate which was signed with our private registration authority (CA). The private key (type ECC) was generated on the device itself - to be more specific directly on the on-board TPM. The public key is included inside the device certificate.
Now we have a use-case where we want to en... |
For a KEM mechanism like RSA, Kyber, etc. is there it usually worth doing key trapping/key encapsulation both directions in a key exchange? By this I mean: Alice wraps a symmetric key and sends it to Bob. Bob wraps a different symmetric key and sends it to Alice. They both then run the concatenation of these two keys i... |
I asked an AI the following question:
Can you provide me with random numbers of 30 digits in length?
And then the AI has generated these numbers for me.
563958422461839604397274590248
743298571529845197630149526734
962345019834590239458293827563
841259630492576302945836184025
129458392650293745092837563945
9384750298... |
I have a theoretical question about the probability of collisions of hashes versus random numbers. I'm not interested in the exact probabilities. The exact hash function is not relevant (we can assume it is perfectly uniform, cryptographically strong, etc.). The implementation of the random number generator is also not... |
(Sorry for a newbie question)
In ECC the intent is to create a group of a prime order (or prime multiplied by a relatively small cofactor).
I know there's an algorithm for ECC to count the number of elements. My question is: how is it known that the group order is indeed prime? AFAIK there're no known deterministic alg... |
The use case here is to deterministically generate a multi-use wallet from a single 12-word BIP39 mnemonic. Currently a standard process for deriving secp256k1 keypairs is implemented, e.g., using a derivation path like m/44'/60'/0'/0/x for an arbitrary x (0, 1...) to derive keypairs, which include a 32 byte/256 bit p... |
I am learning about Elliptic curve scalar multiplications and I am on NAF, and I am trying to figure out the concept.
What I understand is if I have K=27 with using NAF the binary looks like this 100-10-1 then the scalar multiplication process like this: 2(2(2(2(2P))-P))-P which is 5DBL and 2ADD.
My questions is if wan... |
Should you hash the salt on its own ? Is that possible?
for example being password with salt appended at the end hash(pass || salt) and hash(salt) in a password file?
|
I have a pytorch model that generates bond trade pairs that have a high probability of reverting to the mean in a 30 day time period.
I want to sell the signals, but I do not want them to be redistributed. Is there a way to encrypt my data signals, if I put them on a marketplace like Amazon Data Exchange or Snowflake?
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This is the problem
Let $\mathcal{L}$ be a lattice and $v_1,v_2,\ldots,v_n\notin\mathcal{L}$. Given the values $a_1,\ldots,a_n$ such that
$$a_1=\lfloor v_1\rceil+v_2+\ldots+v_n$$
$$a_2=v_1+\lfloor v_2\rceil+\ldots+v_n$$
$$\vdots$$
$$a_n=v_1+v_2+\ldots+\lfloor v_n\rceil$$
where $\lfloor\cdot\rceil$ means projection to $... |
I'm trying to understand the exploitability of the padding oracle attack, which enables someone to decrypt and encrypt the contents without knowing the encryption key.
Can encrypted data with the first block, be decrypted by the app that relies on a static IV without knowing the IV?
I want to understand the padding o... |
The implementation of Shamir secret sharing in this code, only generates the original image if the shares are provided in consecutive order (ex: [2,3,4]) and won't work in any other share order (ex: [2,4,6] or [4,1,3]). However, Shamir secret reconstruction does not require the shares to be in any order, then why does ... |
I want to wrap a private key out of a HSM, using an external EC key pair (master key) and then verify that I can recover it.
The wrapping occurs as follows:
Generate a secret AES key in the HSM, using the public part of the EC master key, the private part of the internal key pair and the derivation mechanism CKM_ECDH1... |
In the paper Efficient and Secure Pairing-Free Certificateless Aggregate Signature Scheme for Healthcare Wireless Medical Sensor Networks, on the signature generation part (Page 5), there is an equation $Y_{2i} = [(y_2x_i + h_{2i}d_i)modq]P_{Pub} = (u_i, v_i)$.
How is a group element assigned to two integers? $u_i$ is... |
I need to sign a URL to make sure the URL cannot be tampered or forged.
The client has limited capabilities and I cannot use a key which is more than 50 characters long.
Generally I use RSA to generate the signature, with keys of the proper size.
So I am not sure what technique to use to keep the signature safe enough.... |
In PKCS#11 documentation § 2.1.23 is described how to wrap and unwrap a target asymmetric key of any length and type using an RSA key, called CKM_RSA_AES_KEY_WRAP. This mechanism could be easily implemented by hand in case it is not available in HSM.
The counterpart exists for EC, CKM_EC_AES_KEY_WRAP can wrap and unwra... |
I need a way to encode a set of information in a way that the result would be as short as possible with a requirement of it being usable as part of URL string.
I don't really care that much about security, the encryption is applied mostly for the plain text to not be visible right away. At the same time, just encoding ... |
I received two distinct outcomes from a single input using SHA3-256 and KECCAK-256:
input --> sha3-256 --> output1
input --> keccak-256 --> output2
I want to find input2, which will give me output1 after Keccak-256 hash :
input2 --> keccak-256 -> output1
Is it somewhat possible? I read somewhere that SHA3-256 and ... |
I find it hard to fully grasp the whole Pinocchio protocol
.
I understand that the $\alpha$ s are for restricting the prover to compute only the corresponding set-up values.
But it's not clear for me to pick up $\gamma$ for the consistent(same) witness check.
From what I can tell, this protocol cleverly embedded differ... |
I have found myself in a position where I need to encrypt multiple objects (vCards) with AES Counter mode or Galois/Counter Mode using the same key. Now here is the problem the structure of the vCard always starts with predefined values i.e. here is an example from wikipedia
BEGIN:VCARD
VERSION:4.0
FN:Simon Perreau... |
This is Dan Boneh's video on PLONK - https://www.youtube.com/watch?v=vxyoPM2m7Yg
I went through the video multiple times & also tried to go through the original PLONK paper - https://eprint.iacr.org/2019/953.pdf
Boneh's explanation of PLONK involves the steps
1) Boneh consider's the trace of the equation as the inputs ... |
Is there a lossless compression algorithm that has hashing-like properties where there are multiple solutions to it?
As in for example, when a 1000-bit data-sequence is compressed into a 500-bit data sequence, there are multiple possible 500-bit data sequences that can be generated as outputs. Each of these 500-bit dat... |
Backgroud: I am reading the paper "Learning a Parallelepiped: Cryptanalysis of GGH and NTRU Signatures". (here is the link). And I got stuck in understanding the computation of moment.
Question statement: In section 4.3 of the paper, It defined: For any $V=[\mathbf{v}_1,\cdots,\mathbf{v}_n] \in GL_n(\mathbb{R})$ and an... |
We are planning to organize a workshop with the participation of academicians, engineers and graduate students working in the field of cryptology. On the first day, we are planning a fun competition for the participants as an ice-breaking event. Our goal is to organize a quiz on fun, little-known facts about cryptology... |
This may be a stupid question but I've been stuck on parsing these definitions for a while.
I am reading the paper "On Ideal Lattices and Learning with Errors Over Rings" by Lyubashevsky, Peikert, and Regev. I am trying to understand the error distributions they are proposing. In section 3, they define a set $\mathbb T... |
Finding a cryptography library to implement various application features is not difficult nowadays, thanks to options like NaCl, Google Tink, PyCA, and OpenSSL.
However, I've been struggling to find a library that supports group signatures, which is causing confusion. Would anyone be able to provide an explanation or r... |
I am trying to understand STARK with not much math. I understand SNARK like this:
Computation → Arithmetic Circuit → R1CS → QAP → zk-SNARK
From the helpful article: https://z.cash/technology/zksnarks/
We have a computation with many steps that can prove something. We take that and create an arithmetic circuit (in simpl... |
Suppose we have a standard $\Sigma$-protocol for proving the knowledge of a witness $x$ for the statement $y$. It has an honest-verifier ZK and special soundness. Now we do an unusual modification to get an interactive $\Sigma'$-protocol in ROM:
The prover $\mathcal{P}$ compute $a$ exactly like in $\Sigma$-protocol an... |
I am trying NIST SP 800-22 to test the randomness of 128 bit output in AES, but i always get igamc: UNDERFLOW or Segmentation fault (core dumped) error.
My data file has 128 bit output format, for example as follows:
0110110001000101111101110101001101100000010111100111110001001011101111100101001110110100000011101101110... |
I'm a dev new to security and cryptography.
I'm writing a password manager and Time-based OTP combo in dart/flutter to use in multiple devices and platform for fun and use it personally for real. I have done some reading over google, stackoverflow.com and crypto.stackexchange.com, came up with following skeleton, and h... |
I would like to investigate if it is possible to introduce Differential Privacy (DP) to a model via both adding Laplacian noise to the training data and then training with DP-SGD updates. Is it a valid way to introduce DP ?
In other words, if we separately applied Laplacian noise to the data the system would be assigne... |
According to FIPS 186-4 § D.1.1.5 Choice of Base Points I should be able to create ECDSA signatures with custom base points on P-256 (secp256r1).
Does standard PKCS#11 support this feature?
This is how far I got building example code, based on org.xipki:ipkcs11wrapper:1.0.4 and SoftHSM 2.6.1:
import org.xipki.pkcs11.wr... |
Consider a system where DES is used to encrypt HTTP GET requests. The first three bytes correspond to the character sequence "GET". How many encrypted messages is it necessary to intercept to be sure to guess the key used to encryption ?
|
I'm using the Rivest Shamir Wagner Time Lock Puzzle setup in an application, leveraging Pietrzak's algorithm for generating the proof.
My question has to do with selecting a proper starting point. In this paper the authors talk about verifying that the starting point is a modular square root. They discuss the choic... |
Is it theoretically possible to use homomorphic encryption to run an encrypted algorithm over encrypted data?
If this is not possible, is it at least possible to run an encrypted algorithm over plain data (beyond a plain algorithm over encrypted data)?
Ideally, can you cite papers where I can read about it?
|
Does the order of Lagrange interpolation have any role in reconstructing the secret key in Shamir's secret share?
|
Is it possible to find a secure curve which's base field is the scalar field of secp256k1?
In general, can you find a secure curve defined over the scalar field of any secure curve? (For example, a secure curve defined over the scalar field of ed25519?)
Edit: Using the same parameters as secp256k1 (in short Weierstrass... |
The OpenSSL 3.0 rand function's DRBG uses the getrandom() system call to get 48 bytes of secure entropy from the kernel. It also uses other information like the system uptime, available RAM, and other factors public in user space. So if the getrandom() function is compromised by an adversary using a rootkit, how would ... |
In my application I have an SQLite database that stores labels for images, like this:
IMAGE ID
LABEL
1
foo
1
bar
2
bar
3
foo
The LABEL column is indexed as it is important that I can efficiently find all images with a certain label.
At rest I would like to encrypt those labels so that no one can learn... |
Consider a Tor hidden service. I want to retrieve the main page of such website in such a way that I can later prove to a skeptical third party that the website with this certificate (identified by the public key in the address) provided me with this exact HTML page.
Is this possible assuming the website does not insta... |
I want to use a data structure like merkle tree in a hypothetical blockchain that, if needed, can fast check whether a wallet/account has received directly or indirectly from a specific list of wallets/accounts in the past. And in an ideal case, how much of the current balance of this wallet has been received from the ... |
Specifically if we know the $r$ takes values from the set $\{0,1\}$and $c=g^r*h^m$ does the hiding property still hold? I think I already managed to prove that the binding property holds due to the difficulty of the Dlog problem and my intuition says that the hiding property is compromised. But I can't seem to figure o... |
I am reading this explanation of zkSnark written by Maksym Petkus - https://arxiv.org/pdf/1906.07221.pdf
In page 24, the zk-SNARK of polynomial is explained. In setup phase, the proving and verification keys are created by a trusted setup. I understood how proof is created using the proving key.
However, if we see the ... |
Where can I find a clear algorithm diagram of SPECK algorithm? I want to follow steps to write ARM assembly code.
|
I recently read the article on the threshold signature scheme “Fast Multiparty Threshold ECDSA with Fast Trustless Setup” and I have a question.
In the key generation section, each player $P_i$ selects $u_i$ and then performs a $(t, n)$ Feldman-VSS of the $u_i$ value. In this case, other participants can make use of La... |
I'm having problem proving the following, I intuitively think this is correct but can't formally prove why.
given a PRF $F_k(x)$
proove that the following is also a PRF
$$
F'_k(x) = \begin{cases}
F_k(x)&\text{if }k\neq0\\
\\\text{const(some const value)}&\text{if }k=0
\end{cases}
$$
I found my mistake, I did not use... |
Suppose we sign and verify messages with a DSA scheme. Before signing the first
message the necessary parameters $(p,q,h,g,x,y)$ are initialized, including the nonce $k$ as an integer between $(1,q-1)$.
For each message, this value is increased by a fixed amount $b$. Therefore it grows linearly .
How can I prove that t... |
I have a request in which I get a series of data in clear (nothing encrypted) and a MAC / authentication tag.
The question is whether the MAC should be validated first or if the fields are filled in or are numerical (or similar validations). I have always considered that the MAC must be validated first, however, I can... |
On an exam I recently took, one of the questions was:
Consider the following signature scheme. The public key is $(p,g,g^x)$, where $p$ is a large prime number. $g$ is a generator of $\mathbb Z^*_p$, and $x$ is a random number in $\mathbb Z_{p-1}$. The secret key is $x$. The scheme also uses a public hash $H(M)$ that ... |
I recently took an exam where one of the questions was roughly the following:
You need a specific way for sender S to send a large file M to a receiver R with their secret-public key pair, without interaction. You cannot use interactive key exchange protocols. The receiver’s public key is assumed to be authentic. The ... |
I'm currently working on a distributed consensus-based system. I currently give the system a private key through a threshold encryption model, and I want to be able to take some data encrypted with the network's public key and re-encrypt it with an arbitrary public key without any member of the network knowing what the... |
Hello I am trying to understand why the Sidelnikov-Shestakov attack doesn't work for McEliece cryptosystem based on Goppa codes whereas it works when based of GRS codes.
I understood how the attack works but I don't see why it fails with Goppa codes since they are quite similar than GRS codes.
On the 2007 paper https:/... |
Normally I use Argon2 to generate an encryption key, and then use AES to encrypt data with that key.
Can I just set the hash size to be equal to the data size, set the associated data to a random value, and then just use Xor on the Argon2 output to encrypt/decrypt the data instead? Or are there some cryptographic prope... |
I am simply wondering what the bit-length in the algorithm variant in the table below refers to? For the hash functions I assume that this refers to the ouput length in bits. For instance for SHA3-256 this means the hash will be of 256 bits in length. Is this correct?
But, then, what does the 256 mean for the XOF SHAKE... |
I have built a small password manager desktop app using python. This app falls under the master-password model.The app connects to two databases stored locally. The first database stores the users username for my app and the hashed (sha256+salt) master password it also stores an email for password recovery puprpose. Th... |
Use Case:
Web application accessed in browser. Registered users can store personal notes in the application, these notes are stored in a SQL database on a online server. The user can store unencrypted notes and encrypted notes. For unencrypted notes the process is trivial, just store the notes in the database. For encr... |
I was wondering whether quantum-computers really break Schnorr's signature scheme. Schor's algorithm works via the quantum Fourier transform, which reveals the cycle time and thus phi. However, with a multiplicative group mod $q$, a prime, everyone knows the cycle time, but that isn't the problem (unlike RSA). The prob... |
I store the ciphertext and the nonce in a SQL database.
If I decrypt the ciphertext change it and encrypt it again I generate a new nonce, so that I do not encrypt two different plaintexts with the same nonce. After encrypting the updated plaintext I store the ciphertext and the new nonce back to the database.
My quest... |
It is a bit stupid question, but I am so confused. Please examine my explanation. What is the space that exponents the generator $g$ of a cyclic group $G$ of prime order $p$?
I think it is $\mathbb{Z}_p$ since $|G|=p$, so that $G=\{g^0, g^1, \ldots, g^{p-1}\}$. Thus the space that the exponents live is $\mathbb{Z}_p$, ... |
From the PLONK paper.
On pages 19 & 20, the paper describes the prescribed permutation check in PLONK.
In the last step of the proof, these are the checks
a) $L_1(a)(Z(a) - 1) = 0$
b) $Z(a)f'(a) = g'(a)Z(a \cdot g)$
In (a), I think checking $Z(a) - 1 = 0$ & doing the (b) check as written is enough. What purpose does m... |
Do you know a blockchain that does not use at all cryptographic primitives standardized by USA or other countries? It is strange to me that the security of many cryptocurrencies is based on ciphers, hash functions, elliptic curves, etc. from American standards.
It is normal when a cryptographic product contains standar... |
The CEO of the organization XYZ decides to hold a vote to decide whether employees should be allowed to work from home (WFH) either one, two or three days a week.
All 4 employees of XYZ (excluding the CEO), need to vote either “WFH one”, “WFH two” or “WFH three”. To ensure privacy, the CEO asks employees to send their ... |
Given some group in which both discrete logarithms and the computational Diffie-Hellman problem are hard. Furthermore, two random, unrelated group generators $G_1, G_2$, and a third generator defined by $H = G_1 + G_2$. Can you compute $xG_1$ if you know only $G_1$, $G_2$, and $xH$?
My guess: I would assume it's hard, ... |
How do we know that hash functions cannot be reversed? An example is often given of two primes and their product, but any composite number that is the product of two primes has, by definition, exactly 2 natural factors. In the case of hash functions, things are different.
Have there been attempts to reverse hash functi... |
I am constructing a two-party OR gate and trying to do this with oblivious transfer. Yet I am very new to oblivious transfer, wishing to know whether the following construction makes sense.
Goal: Alice inputs a random bit $a$, Bob inputs a random bit $b$, and Bob outputs the logical OR bit $a\oplus b$.
Construction via... |
Suppose that Peggy(prover) and Victor(verifier) are running some zero knowledge proof protocol that does not rely on hidden verifier secrets. The verifier generates randomly chosen challenge values only. Such protocols can be Fiat-Shamir transformed into NI(non-interactive)ZKPs.
There is significant work on NIZKPs. Usi... |
Here is a CTF crypto challenge likes(its write up is public on https://ctftime.org/writeup/15438):
$$N = p*q\\
c1 = (2*p + 3*q)^{e_{1}} mod N\\
c2 = (5*p + 7*q)^{e_{2}} mod N$$
After i transform these:
$$(c^{e_2}_1)\equiv (2p)^{e_1e_2}+(3q)^{e_1e_2}\pmod{N}\\
(c^{e_1}_2)\equiv (5p)^{e_1e_2}+(7q)^{e_1e_2}\pmod{N}$$
Afte... |
When attacking RSA with Square&Multiply, one can figure out the secret key by looking at the exponentiation algorithm itself. To prevent this in software, we could use dummy multiplications after each square.
Yet, there are attacks like correlation power analysis on AES, which is vulnerable to it by definition. How can... |
I have some questions about the setting of the one-way authenticated key exchange of Kyber.AKE as defined in section 5 of the paper.
How does $P_2$ authenticate itself to $P_1$? It is not obvious to me in the paper how it is ensured that $P_1$ really communicates with $P_2$. So how does $P_1$ know that it can actually... |
Could anyone explain me the difference between "key_share" extension and "server_key_exchange" message in TLS (1.3) ?
If I understood right, these "packets" of data are used to send a key material to generate premaster keys. But what's the difference ?
In which case a server must use one or another
|
From the PLONK paper.
On pages 19 & 20, the paper describes the prescribed permutation check in PLONK.
------------------------------------------------------------------------------------------------
My question is about the Step 3 in the protocol which I have marked in red
I am interpreting $1 \le j < i$ as $j =1$ to... |
When I want to encrypt a 16 byte long message with AES-128-CBC using int TLS 1.2 do I need to add a 16 byte block of padding or can I just encrypt the message without padding ?
|
For example is it harder to break one 256 bit encryption than two 255 bit encryption for RSA and AES?
For example, I understand that 256 bit RSA can be cracked in one minute according to this article [1] So would two independent 255 bit RSA message take thirty seconds each, and four 254 bit messages take 15 seconds eac... |
When using AES-256 (cipher mode CBC and padding mode PKCS7) in combination with HMAC-SHA for authenticated encryption (assuming alternatives like TLS and AES-GCM cannot be used),
should we use SHA-256 or SHA-512?
This answer seems to indicate SHA512.
Is this interpretation correct?
I've seen an implementation using SH... |
I need to implement a Merkle tree using a 128 bit hash function. In general, any hash function that guarantees pre-image, second pre-image and collission resistance should be fine to implement a Markle tree. Is it correct? Probably, it is not even necessary to have pre-image resistance as long as the other two properti... |
Alice has master EC key pair: $a$ - private key, $A$ - corresponding public key
Bob generates 2 random integers $r_1$ and $r_2$ and wants Alice to derive 2 new key pairs:
$a_1$ = $a$ + $r_1$ and $a_2$ = $a$ + $r_2$ and corresponding public keys $A_1$ and $A_2$
Questions:
Is it possible for Alice to prove that she deri... |
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