instruction stringlengths 15 30k |
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Given the existence of unbreakable encryption algorithms, why do we routinely use algorithms that are only resource-intensive to break? |
How to calculate Correlation, Difference propagation probability and Algebraic complexity a particular S-box? |
Let $(X, Y, Z)$ be a set of binary strings of length $n$. Let random $X$ be the private key for encoding (or decoding) message random $Y$ as $Z$. Let the encryption algorithm $m$ be a matching function, i.e., for $m(X, Y) = Z$, if $x_i = y_i$, $z_i = 1$, otherwise $z_i = 0$. Now, $m$ is clearly not a one-way function: ... |
Given the existence of provably-hard-to-solve problems, why do we routinely rely on conjectured-to-be-hard problems for encryption? |
In many proposed lattice PKE schemes, the plaintext is encoded or modulated in a simple fashion, e.g. using Kyber-ish notation:
- key gen: $pk=(A, t=As+e)$, $\quad sk=s\quad$ ($A$ random, $s$, $e$ small random)
- encrypt: $u=A^tr+e_1$, $\quad v=\langle r,t\rangle +e_2+\tilde{m}\quad$ ($m$ message, $r$, $e_1$, $e_... |
Let {(q, G<sub>1</sub>, G<sub>2</sub>, G<sub>T</sub>, e: G<sub>1</sub> * G<sub>2</sub> -> G<sub>T</sub>)<sub>s</sub>} be a family of bilinear groups parameterized by the security parameter s. We use g<sub>1</sub> (resp. g<sub>2</sub>) to denote the generator of G<sub>1</sub> (resp. G<sub>2</sub>).
The XDLIN problem ... |
How to determing if a bilinear map satisfies XDLIN? |
Let $\{(q, G_1, G_2, G_T, e: G_1 \times G_2\to G_T)_s\}$ be a family of bilinear groups parameterized by the security parameter $s$. We use $g_1$ (resp. $g_2$) to denote the generator of $G_1$ (resp. $G_2$).
The XDLIN problem is to guess bit $B$ ($B = 0$ or 1), given
$$P_B:= \{g_1^a, g_1^b, g_1^{ac}, g_1^{bd}, g... |
How to determine if a bilinear map satisfies XDLIN? |
I saw a statement that the probability of finding a key $k'$ to simulate 3 keys $k_1$, $k_2$, $k_3$ is neglectable:<center> $\mathrm{Enc}(k_3,\mathrm{Enc}(k_2,\mathrm{Enc}(k_1,x))) = \mathrm{Enc}(k′,x)$ </center>
When not considering MITM attack, the probability of brute forcing triple DES is $1/2^{168}$.
... |
Bulletproof and dory reduce the witness size by a half during each interaction, until the witness is compressed to be only one element. But what about the witness is not precisely exponential size? Can we still use the two schemes by padding the witness? |
Can we pad witness of bulletproof and dory to be exponential size? |
Let's suppose I have a 8-bit substitution box composed of 256-bytes and invert it.
Does changing one byte in the substitution box will make the inverse result completely different than if I didn't change it?
Or will only the changed byte be different in the inverse S-box? |
How changing a single byte/word in a substitution box affects the inverse result? |
How to find linear complexity of non binary prime fields using berlekamp_massey algorithm in Sagemath? |
Due to protocol limitations, I can put in 24 bytes of data only for tx (excluding headers), if I use AES_GCM for encrypting my data, I understand I don't need to worry about padding.
For instance, if my data is 22 bytes, I would be getting a 22 bytes encrypted output. So, I had zero-ed in on AES-GCM or AES-CTR. How... |
We use DES in cipher feedback mode (CFB) to encrypt a plaintext m = m1m2 . . . m100 into a ciphertext c1c2 . . . c100, where each mi is 8-bit long. The ciphertext is sent to Bob. If c15 and c25 are missing and c8 and c88 are received as c′8 and c′88 wrongly, what mi’s can B compute correctly from the received ciphertex... |
We use DES in cipher feedback mode (CFB) to encrypt a plaintext $m = m_1\mathbin\|m_2\mathbin\|\ldots\mathbin\|m_{100}$ into a ciphertext $c_1\mathbin\|c_2\mathbin\|\ldots\mathbin\|c_{100}$, where each $m_i$ is 8-bit long. The ciphertext is sent to Bob. If $c_{15}$ and $c_{25}$ are missing and $c_8$ and $c_{88}$ are re... |
We use DES in cipher feedback mode (CFB) to encrypt a plaintext $m = m_1\mathbin\|m_2\mathbin\|\ldots\mathbin\|m_{100}$ into a ciphertext $c_1\mathbin\|c_2\mathbin\|\ldots\mathbin\|c_{100}$, where each $m_i$ is 8-bit long. The ciphertext is sent to Bob. If $c_{15}$ and $c_{25}$ are missing and $c_8$ and $c_{88}$ are re... |
We use DES in cipher feedback mode (CFB) to encrypt a plaintext $m = m_1\mathbin\|m_2\mathbin\|\ldots\mathbin\|m_{100}$ into a ciphertext $c_1\mathbin\|c_2\mathbin\|\ldots\mathbin\|c_{100}$, where each $m_i$ is 8-bit long. The ciphertext is sent to Bob. If $c_{15}$ and $c_{25}$ are missing and $c_8$ and $c_{88}$ are re... |
We use DES in cipher feedback mode (CFB) to encrypt a plaintext $m = m_1\mathbin\|m_2\mathbin\|\ldots\mathbin\|m_{100}$ into a ciphertext $c_1\mathbin\|c_2\mathbin\|\ldots\mathbin\|c_{100}$, where each $m_i$ is 8-bit long. The ciphertext is sent to Bob. If $c_{15}$ and $c_{25}$ are missing and $c_8$ and $c_{88}$ are re... |
We use DES in cipher feedback mode (CFB) to encrypt a plaintext $m = m_1\mathbin\|m_2\mathbin\|\ldots\mathbin\|m_{100}$ into a ciphertext $c_1\mathbin\|c_2\mathbin\|\ldots\mathbin\|c_{100}$, where each $m_i$ is 8-bit long. The ciphertext is sent to Bob. If $c_{15}$ and $c_{25}$ are missing and $c_8$ and $c_{88}$ are re... |
We use DES in cipher feedback mode (CFB) to encrypt a plaintext $m = m_1\mathbin\|m_2\mathbin\|\ldots\mathbin\|m_{100}$ into a ciphertext $c_1\mathbin\|c_2\mathbin\|\ldots\mathbin\|c_{100}$, where each $m_i$ is 8-bit long. The ciphertext is sent to Bob. If $c_{15}$ and $c_{25}$ are missing and $c_8$ and $c_{88}$ are re... |
We use DES in cipher feedback mode (CFB) to encrypt a plaintext $m = m_1\mathbin\|m_2\mathbin\|\ldots\mathbin\|m_{100}$ into a ciphertext $c_1\mathbin\|c_2\mathbin\|\ldots\mathbin\|c_{100}$, where each $m_i$ is 8-bit long. The ciphertext is sent to Bob. If $c_{15}$ and $c_{25}$ are missing and $c_8$ and $c_{88}$ are re... |
I need to encrypt some user's data. However to make it more apparent to the user what data is stored in each key, I was thinking to also store the length of the actual data along the cipher.
E.g.
```
user_1_secrets = [
{
"key": "mysecret"
"encrypted_data": b"abf4c2",
"length": "10",
},
{
... |
Hi I am currently developing a research project, but it seems that my implementation of Pedersen commitment is not efficient. <br/> I wonder if there are any efficient implementation of Pedersen commitment in c++?<br/> Or if using things like ECC would boost the efficiency(seems number of bits could be smaller), or do... |
In many proposed lattice PKE schemes, the plaintext is encoded or modulated in a simple fashion, e.g. using Kyber-ish notation:
- key gen: $pk=(A, t=As+e)$, $\quad sk=s\quad$ ($A$ random, $s$, $e$ small random)
- encrypt: $u=A^tr+e_1$, $\quad v=\langle r,t\rangle +e_2+\tilde{m}\quad$ ($m$ message, $r$, $e_1$, $e_... |
What is the name of this kind of cipher? (algorithm and description provided) |
In Openssl, is there a way to systematically generate a private key such that every time you perform this key derivation, you produce the same private key? It seems like every openssl command that generates private keys does so randomly. So, if you lose your private key file for whatever reason, there's no practical me... |
In Openssl, is there a way to systematically generate a private key such that every time you perform this key derivation, you produce the same private key? It seems like every openssl command that generates private keys does so randomly. So, if you lose your private key file for whatever reason, there's no practical me... |
I designed 8 bit lfsr in vhdl. According to mathematical theory, I xor processed the outputs of registers 1, 4, 5, 6 and 8 and connected them to the input of register 1. theory says that if I give the inputs the polynomial "10111000", I get the repetition of (2^8)-1.
I tried some more. And I tried the circuit withou... |
What is the result of not connecting the 1st register to the xor gate in LFSR? |
I designed 8 bit lfsr in vhdl. According to mathematical theory, I xor processed the outputs of registers 1, 4, 5, 6 and 8 and connected them to the input of register 1. theory says that if I give the inputs the polynomial "10111000", I get the repetition of (2^8)-1.
I tried some more. And I tried the circuit withou... |
I designed 8 bit lfsr in vhdl. According to mathematical theory, I xor processed the outputs of registers 1, 4, 5, 6 and 8 and connected them to the input of register 1. theory says that if I give the inputs the polynomial "10111000", I get the repetition of (2^8)-1.
I tried some more. And I tried the circuit withou... |
Hi I am currently developing a research project, but it seems that my implementation of Pedersen commitment is not efficient. <br/> I wonder if there are any efficient implementation of Pedersen commitment in c++?<br/> Or if using things like ECC would boost the efficiency(seems number of bits could be smaller), or do... |
In **Openssl**, is there a way to systematically generate a private key such that every time you perform this key derivation, you produce the same private key?
It seems like every openssl command that generates private keys does so randomly. So, if you lose your private key file for whatever reason, there's no prac... |
I am going over the paper https://verifiable-timed-signatures.github.io/web/assets/paper.pdf and on page 5, it says the following:
Suppose I have a t-out-of-n threshold sharing scheme for the secret $\sigma$. The first $t-1$ shares are defined as $\sigma_i = H(m)^{\alpha_i}$, where $\alpha_i$ are sampled randomly in... |
I am going over the paper https://verifiable-timed-signatures.github.io/web/assets/paper.pdf and on page 5, it says the following:
Suppose I have a t-out-of-n threshold sharing scheme for the secret $\sigma$. The first $t-1$ shares are defined as $\sigma_i = H(m)^{\alpha_i}$, where $\alpha_i$ are sampled randomly in... |
I noticed that it seems the original Plonk paper introduced that there were two extensions with state width = 3 or 4 (as described in https://github.com/matter-labs/proof_system_info_v1.0/blob/master/README.md). I recently reviewed some code and they set the state width = 5 and set the verification key as follows.
... |
How to choose the value of state width of Plonk with lookup? |
I designed 8 bit lfsr in vhdl. According to mathematical theory, I xor processed the outputs of registers 1, 4, 5, 6 and 8 and connected them to the input of register 1. theory says that if I give the inputs the polynomial "10111000", I get the repetition of (2^8)-1.
I tried some more. And I tried the circuit withou... |
OK, it is a question of what the connection polynomial is, the figure helps clarify what you are doing. In both cases the polynomial is degree 8.
Originally, your connection polynomial is
$1+x+x^4+x^5+x^6+x^8$ (I wrote it in the order of the LFSR connections). This polynomial is not primitive, it's not even irredu... |
I'm trying to find a way to have multi party hash computation, more specifically for SHA256. I want for two people to be able to compute a hash so that any of them knows the pre-image but when they get together they can reconstruct it.
Is there any known way to do it in general or any hack that can be used in the S... |
Is there a way to calculate a hash with two people so that no one knows the pre-image but if they get together they do? |
I'm trying to find a way to have multi party hash computation, more specifically for SHA256. I want for two people to be able to compute a hash so that none of them knows the pre-image but when they get together they can reconstruct the pre-image.
Is there any known way to do it in general or any hack that can be u... |
Certain cryptographic hash functions based on number-theoretic problems, such as Rabin's hash function $x^2\bmod N$, are known to be broken by a quantum computer. For example, one could use Shor's algorithm to factor $N$ into the product of two primes $(p_1,p_2)$, and hence find collisions at-will. Alternatively it's... |
Is there a family of cryptographic hash functions that can be realized with a smallish depth quantum circuit? |
on the wiki page of Rustdesk, it states "the connection is unecrypted, please do not send us issue about this." for local direct IP.
BUT, Rustdesk is intended "Virtual / remote desktop infrastructure for everyone! ", (so not localdesktop)
While Rustdesk claims Rustdesk is encrypted between client and server, whic... |
Is that possible for local p2p connection with encryption and remote p2p connection with encryption within the same application? |
> can we have p2p connection with encryption locally (without a server) and remotely (with a relay server) within the same application?
Certainly, it's possible - the application (probably) needs to know which mode any specific connection is using (direct or relayed) in order to know who it is supposed to authentica... |
Certain number-theoretic cryptographic hash functions, such as $x^2\bmod N$, are known to be broken by a quantum computer. For example, one could use Shor's algorithm to factor $N$ into its product of two primes $(p_1,p_2)$, and use these primes to find collisions at-will. It's also been a long-open problem to find a... |
If we do not encrypt a message, we can use a checksum to check data integrity. For authenticated encryption, we no longer need the checksum because we use the authentication tag to verify data integrity.
The above is about error-checking. Now, for error correcting (like Hamming code), is there an encryption scheme ... |
Error-correcting as part of an encryption scheme? |
Lets consider a hypothetical situation.
What would be the implications if there is a method by which one can calculate the public keys for incremental private keys, with the help of only public key?
For instance, one is given public key only. (that public key has the private key as 1001) and he is asked to calculate... |
Implications of generating public keys for incremental private keys? |
Is SHA-3 normally used with a LUT or hash table? |
Outside of use in microchips and FPGAs does SHA-3 have a lookup table? |
I am going over the paper https://verifiable-timed-signatures.github.io/web/assets/paper.pdf and on page 5, it says the following:
Suppose I have a t-out-of-n threshold sharing scheme for the secret $\sigma=H(m)^\alpha$. The first $t-1$ shares are defined as $\sigma_i = H(m)^{\alpha_i}$, where $\alpha_i$ are sampled... |
> Outside of use in microchips and FPGAs does SHA-3 have a lookup table?
(I'm answering the title and the question; the question might be interpreted as 'do you use SHA-3 to implement a LUT or hash table?')
Well, some implementations have the per-round constant in the Iota transform stored as a look up table (how... |
Let us consider a hypothetical situation.
What would be the implications if there is a method by which one can calculate the public keys for incremental private keys, with the help of only the public key?
For instance, one is given a public key only. (that public key has the private key as 1001) and he is asked ... |
I'm relatively new to the field of security.
I'm working on an IoT system with WiFi-connected nodes (Bio-sensing devices) communicating with a server for centralized monitoring.
I need to authenticate each device when connecting to the server.
So, each device has a unique certificate with a signature (ECDSA).
... |
How to authenticate multiple IOT devices having unique certificates (ECDSA)? |
Hypothetically,
1. IF we were to create a SSL/TLS or QUIC ciphersuite from a single (unkeyed) permutation operating in sponge mode to provide hashing and duplex mode to provide AEAD cipher,
2. AND IF the permutation is wide enough, and the capacity in both modes are large enough,
3. THEN, to what extent can... |
Secure ciphersuite from security-wise sub-optimal unkeyed permutation? |
> Each device has a unique certificate with a signature (ECDSA).
Every certificate contains the public key of the certificate owner, and a signature of the certificate's content (including public key) by the certification authority that issued the certificate. "ECDSA" is somewhat unclear: we do not know if that appl... |
> Each device has a unique certificate with a signature (ECDSA).
Every certificate contains the public key of the certificate owner, and a signature of the certificate's content (including public key) by the certification authority that issued the certificate. "ECDSA" is somewhat unclear: we do not know if that appl... |
OK, it is a question of what the connection polynomial is, the figure helps clarify what you are doing. In both cases the polynomial is degree 8.
Originally, your connection polynomial is
$1+x+x^4+x^5+x^6+x^8$ (I wrote it in the order of the LFSR connections). This polynomial is not primitive, it's not even irredu... |
Consider following simple RBG where SHA-256 of random noise (more than 200Bytes of 4 bits entropy per byte) is computed to produce 256 output bits
$output = SHA256(randomNoise)$
Is security strength of collision resistance or pre-image resistance applicable to it i.e it provides 128 or 256 bit security?
Acco... |
Consider following simple RBG where SHA-256 of random noise (more than 200Bytes of 4 bits entropy per byte) is computed to produce 256 output bits
$\text{output} = \operatorname{SHA-256}(\text{randomNoise})$
Is security strength of collision resistance or pre-image resistance applicable to it i.e it provides 128 ... |
> Each device has a unique certificate with a signature (ECDSA).
Every certificate contains the public key of the certificate owner, and a signature of the certificate's content (including public key) by the certification authority that issued the certificate. "ECDSA" is somewhat unclear: we do not know if that appl... |
*Let me start by saying that I have a mathematical background, and have very little experience with cryptography. I only know the very basics.*
With that said, I recently read about Homomorphic Encryption (HE), and thought that it was a very interesting concept. What one really cares about, though, is *Fully* Homomo... |
*Let me start by saying that I have a mathematical background, and have very little experience with cryptography. I only know the very basics.*
With that said, I recently read about Homomorphic Encryption (HE), and thought that it was a very interesting concept. What one really cares about, though, is *Fully* Homomo... |
*Let me start by saying that I have a mathematical background, and have very little experience with cryptography. I only know the very basics.*
With that said, I recently read about Homomorphic Encryption (HE), and thought that it was a very interesting concept. What one really cares about, though, is *Fully* Homomo... |
*Let me start by saying that I have a mathematical background, and have very little experience with cryptography. I only know the very basics.*
With that said, I recently read about Homomorphic Encryption (HE), and thought that it was a very interesting concept. What one really cares about, though, is *Fully* Homomo... |
As stated in [RFC8032][1] and [FIPS 186-5][2], Ed25519 signatures uses the following encoding method:
> A curve point (x,y), with coordinates in the range 0 <= x,y < p, is
> coded as follows. First, encode the y-coordinate as a little-endian
> string of 32 octets. The most significant bit of the final octet i... |
Suppose N many messages has been sent from A to B in this format:
- HMAC(K, C(i)) || C(i).
Where C(i) is some cipher-text encrypted with some secure algorithm using some key
K(i) != K for any i in range [0, N-1].
There is no implication whether K(i) = K(j) for any i != j.
Thus, it is just "some" encryptio... |
Is having more than one HMAC provide more information to the attacker? |
Does having more than one HMAC provide more information to the attacker? |
Hypothetically,
1. IF we were to create a SSL/TLS or QUIC ciphersuite from a single (unkeyed) permutation operating in sponge mode to provide hashing and duplex mode to provide AEAD cipher,
2. AND IF the permutation is wide enough, and the capacity in both modes are large enough,
3. THEN, to what extent can... |
I have a question about the decryption in Kyber [\[1\]][1]. I will first give important statements of the paper and then ask my actual question with an example.
----------
In the paper it is stated:
> ... decrypt to a 1 if $v-s^Tu$ is closer to $\lceil \frac{q}{2} \rfloor$ then to 0, and decrypt to a 0 ot... |
I have a question about the decryption in Kyber [\[1\]][1]. I will first give important statements of the paper and then ask my actual question with an example.
----------
In the paper it is stated:
> ... decrypt to a 1 if $v-s^Tu$ is closer to $\lceil \frac{q}{2} \rfloor$ then to 0, and decrypt to a 0 ot... |
Suppose N many messages has been sent from A to B in this format:
- **HMAC(K, C(i)) || C(i)**.
Where
- **C(i**) is some cipher-text encrypted with some secure algorithm using some key
- **K(i) != K** for any i in range [0, N-1].
There is no implication whether **K(i) = K(j)** for any i != j.
Thus, it is... |
Suppose $N$ many messages has been sent from $A$ to $B$ in this format:
- $\operatorname{HMAC}(K, C(i)) \mathbin\| C(i)$.
Where
- $C(i)$ is some cipher-text encrypted with some secure algorithm using some key
- $K(i) \ne K$ for any $i$ in range $[0, N-1]$.
There is no implication whether $K(i) = K(j)$ for ... |
all I am trying to implement the Basic skeleton of the PQC Kyber Algorithm. Until now I have obtained t=As+e and s after performing point-wise multiplication (Frequency to Time domain). Now I got stuck at encode12 algorithm which is required to obtain pk(12xnxk/8+32 bytes) and secret key(12xnxk/8 bytes). Can you please... |
Hi everyone I am trying to implement the Basic skeleton of the PQC Kyber Algorithm. Until now I have obtained t=As+e and s after performing point-wise multiplication (Frequency to Time domain). Now I got stuck at encode12 algorithm which is required to obtain pk(12xnxk/8+32 bytes) and secret key(12xnxk/8 bytes). Can ... |
In adversarial context of MPC, the corruption behavior
refers to the assumptions about the corrupted parties’ deviation level from the protocol
specification. Three main types of corruption behaviors are: semi-honest, malicious, and
covert.
In practice, dealing with semi-honest corruption behavior is considered m... |
In adversarial context of MPC, the corruption behavior
refers to the assumptions about the corrupted parties’ deviation level from the protocol
specification. Three main types of corruption behaviors are: semi-honest, malicious, and
covert.
In practice, dealing with semi-honest corruption behavior is considered m... |
I remember reading a previous stack exchange post (unfortunately was unable to find the link, if someone knows the link that would be great!) about a method to make password checking time for the server be on average less than that for an attacker. Essentially, when the password is first created a random number between... |
How long time does quantum computers take per operation when search the key of Kyber? Grover's algorithm weakens 256-bit AES to 128-bit security, quantum computers at most take 2^128 operations to find AES key, but it must take some time per operation; as mentioned https://www.ambit.inc/pdf/KyberDrive.pdf : Kyber-1024 ... |
How long time per operation to crack Kyber1024 compared to AES256 for quantum computers? |
What is there to say about using a power basis or a tensor basis or some combination of them for the RSIS problem in lattice cryptography?
Restricting to dimension 3 for illustration, usually the basis is $(1,x,y)$ for uniform $x,y\in R$.
I'm instead wondering about power basis $(1,x,x^2)$, and tensor basis $(1,x,x^2... |
Tensor and power bases for SIS? |
The current accepted answer is out of date and somewhat misleading. Disclaimer: I'm an author on the AEGIS Internet Draft I'm about to talk about.
[AEGIS][1] (technically AEGIS-128L and AEGIS-256) has an [Internet Draft][2] and [TLS cipher suite name][3]. It's in libsodium, the Zig programming language standard libr... |
I wonder if there is any scheme or algorithm to generate HMACs that verify with multiple keys.
Suppose I have the secret keys K1, K2 and K3 and I have a message M1. Is the following possible?
- Generate an HMAC1 with M1 that can be verified with K1 and K2 but not with K3
- Generate a HMAC2 with M1 that ca... |
Is there a multi-key HMAC scheme? |
In federated learning using homomorphic encryption, all participants in most schemes share the same pair of keys, which can easily cause key leaks and lead to data privacy leaks. After research, I found that someone proposed to use a multi-key homomorphic encryption algorithm to solve the above problems. But I wonder w... |
I have been thinking about this question: if I directly replace the hash function with the message in the BLS signature, does the security of the BLS degenerate from **existential** unforgeability(EUF) to **selective** unforgeability(SUF)?
The modified BLS signature scheme is defined as below.
$\cdot KeyGen()\to... |
Replacing the Hash function with messages in the BLS signature scheme, the security degenerates from EUF to SUF? |
The current accepted answer is out of date and somewhat misleading. Disclaimer: I'm an author on the AEGIS Internet Draft I'm about to talk about.
[AEGIS][1] (technically AEGIS-128L and AEGIS-256) has an [Internet Draft][2] and [TLS cipher suite name][3]. It's in libsodium, the Zig programming language standard libr... |
I have been thinking about this question: if I directly replace the hash function with the message in the BLS signature, does the security of the BLS degenerate from **existential** unforgeability(EUF) to **selective** unforgeability(SUF)?
The modified BLS signature scheme is defined as below.
$\cdot KeyGen()\to... |
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