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Is chaos based cryptography quantum-resistant?

recently I'm learning chaos based cryptography, but it confuses me that whether concrete implement such as chebyshev map-based encryption algorithm quantum-resistant?
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0answers
10 views

Make substitution cipher less easy to decode

What methods exist to make frequency analysis and other attacks on substitution cipher harder to pull? For example: Polyalphabetic: Alternate the substitution of frequent letters or words, so "E" can ...
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0answers
10 views

Unknown bit in the output of encryption of data using SIMECK32 cipher?

How is the unknown bits (annotated by red arrow in figure below) come in the OUTPUT after round 1 and round 2 ? Following is the pictorial representation of SIMECK round function operation. Ref: ...
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0answers
16 views

With node-jose, Should I expect the JWK -> PEM conversion to be reversible?

I am using node-jose to convert a particular JWK to a PEM, and then ... converting that PEM to a JWK. The resulting JWK has the same e, but different n than the original. Should I be surprised? I ...
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0answers
16 views

Identifying encryption & decrypting strange numeric code [closed]

This following encrypted message was posted in my town and me and some friends are trying to solve it but cant come to any conclusions. The message is as follows: ...
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0answers
21 views

Node.js: I have 16 byte key. How can I generate 32 byte key from 16 byte key for AES-256-CBC

I am trying to do decryption in Node.js and encryption in C# with AES CBC 256. I have 16 byte key. I need 32 byte for AES CBC 256 method in Node.js. I tried using Buffer.alloc(32,16-byte-key). I keep ...
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0answers
45 views

Encryption algorithm [closed]

I do not have much knowlegde about cryptography. Can anyone please help me to answer this question: Having just completed a course in cryptography, Tom and Jerry start a new business to manufacture ...
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0answers
21 views

Is an implementation of blinded encryption/decryption mechanism exists?

I want to use 2 semi trusted servers, to decrypt a secret for a user but I don't want those servers to have access to the plain text. Those server need to be able to "partially" decrypt and let the ...
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0answers
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When using Ristretto or Decaf with Ed25519 and Ed448, do scalars still need pruning/trimming/clamping?

Decaf is a point compression method that builds a prime-order group for (twisted) Edwards curves and Montgomery curves with cofactor $h = 4$ based on the Jacobi quartic [H2015]. The promise is to ...
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0answers
10 views

How can we assure Non-repudiation without a personal certificate (eg. using ID authentication) [migrated]

I need a help to understand some specific points about non-repudiation, nonetheless I implemented some authentication methods: Digital Signature Authentication; CHAP (Challenge Authentication ...
2
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1answer
59 views

RSA: Construct private / public key for given cipher and plain text message

let's say we are given a classical RSA encryption scheme, though we would like to "reverse" the task: Given two messages $c, m$ choose $p, q, e$ such that $p, q$ are prime and $c ^ d \equiv m\pmod N$ ...
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0answers
44 views

RSA with a prime substituted by a Carmichael number

If the public key in a RSA system is $(n,e)$ with $n=pq$, $p$ prime, $q <p$ a Carmichael number and $\gcd(e,(p-1)(q-1))=1$ then if $d$ is the inverse of $e$ modulo $k=(p-1)(q-1)$, I want to show ...
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0answers
15 views

How to show that CBC-MAC is not one way mapping? [closed]

Is it possible if the party knows the key, how can i prove that.
1
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1answer
28 views

Testing speed of symmetric vs asymmetric encryption and decryption using gpg

I'm aware that symmetric is faster than asymmetric. I want to test this, but my (obviously incorrect) tests show the reverse. Symmetric test: ...
2
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0answers
28 views

Creating a private cryptocurrency without trusted setup

I am interested in creating a cryptocurrency which keeps the sender, the receiver and the amount private and does not require a trusted setup. I have already read the Zerocash protocol but It uses zk-...
1
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1answer
42 views

Private exponent on RSA key

this is the first time I write here. I'm studying a library to encrypt/decrypt with RSA algorithm. In an example given by the library I found this: ...
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0answers
11 views

How to have a bound (upper or lower) of Gaussion distribution over lattice based crypto>

In lattice-based crypto, we always need to sample 'noise' from Gaussian distribution, but how to measure the bound the noise? For example, if the Gaussian distribution is D_{u,\sigma}, where u is the ...
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4answers
163 views

Is Salsa20+Poly1305 an AEAD?

I see Chacha20Poly1305, XsalsaPoly1305 and AES GCM usually used and mentioned in literature and implementations as AEAD cyphers. My question is that Poly1305 provide authentication and Salsa20 ...
0
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1answer
49 views

I don't understand RSA encryption (specific questions)?

So I've been studying RSA for a class and I'm having a hard time understanding how it works. Why do we choose the value of e such that e is relatively prime to the totient (as opposed to just being ...
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0answers
14 views

Trying to decrypt saml2:EncryptedAssertion (in .NET)

I'm trying to decrypt EncryptedAssertion data (SAML) in .NET Framework: ...
1
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1answer
33 views

Encrypt symmetric session key with asymmetric or symmetric master key?

Every day, I must backup my server's files, encrypt the backup, and upload it to untrusted cloud storage (dropbox, s3, etc.) I've spent time on security.stackexchange where I discovered the typical ...
2
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2answers
64 views

Does cryptographically-secure pseudo random generators require a secure seed?

For any cryptographically-secure pseudo random generators, do we need a secure random seed for those? If the seed is predictable, then everything is broken due to the deterministic propetry of the ...
1
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1answer
31 views

Layman understanding of SHAKE128 XOF

Need some help. I am not versed in hashing and just started programming with PHP and currently need to hash some strings but required it to be unique. Found that OpenSSL can hash with SHAKE128 but ...
2
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0answers
35 views

Error-Correction capabilities of encryption?

This is motivated by this question about the recovery of (corrupted) encrypted files, and in particular the statement (in the answer): But If I know the algorithm and the key and I make a custom ...
0
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0answers
19 views

Point-halving/solving quartic equations over the elliptic curve E(Z_N)/ring Z_N where N = pq

I am wondering whether there are any results/whether there is any knowledge about the following problem: Given a univariate polynomial (say, a quartic) equation defined over $\mathbb{Z}_N$, is it ...
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2answers
73 views

Safest alternative for hashing credit card numbers to use the hash as fingerprint?

Same question asked here in 2014 but since a lot has changed since then, I would like to get feedback from experts on the latest best practices. The problem Our requirement is to provide the ...
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0answers
28 views

(Cracking RSA) How to calculate the Private Key using Public key, p,q,r,n?

I have been given the following values : ...
2
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1answer
66 views

Does Encryption add difficulties to File Recovery?

Seems Yes. People always tell us, it is very hard (or almost impossible) to recover an encrypted hard disk. But after a second thought. I think this is not true. Given that we know the KEY, and the ...
0
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1answer
46 views

Suppose $H(X) \rightarrow Y$ is collision resistant. Is $H$ also one-way?

If we have $H(X) \rightarrow Y$ and it is collision resistant. Can we say that $H$ is also one-way? And if that is true can you give me an example?
1
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1answer
42 views

Can hashes be used to generate larger random numbers?

As far as I understand a hash transforms data into a fixed length representation. For example, a random function returns 8-byte numbers and a hash function has a block size of 32-bytes. If I now ...
1
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1answer
25 views

Does splitting random data reduce its security?

Let's say I've got some securely-generated random data I want to encode as words, 32 bits of it. My wordlist is 2048 words, so each word encodes 11 bits of information. I write a routine to pack ...
2
votes
1answer
54 views

Verify ECDSA signature without data

With RSA PKCS#1 v1.5 it is possible to verify that the signature was generated by the correct private key without actually having access to the data. You just perform the modular exponentiation with ...
0
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0answers
48 views

The Gimli non-linear operator

NORX replaces all the additions of the Chacha20 quarter-round function with the non-linear $x \oplus y \oplus ((x \land y) \ll 1)$ operation. Gimli supposedly improves on it with $x \oplus y \oplus ((...
0
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1answer
30 views

Proving uniform output of CSPRNG

I have a question concerning the paper by Blum, Blum, and Shub introducing the $x^2 \mod N$ Generator. It is clear that the outputs of the generator pass statistical tests for randomness: the larger ...
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0answers
14 views

Implementations of chameleon hash functions [migrated]

For a research project we want to build a proof of concept of a redactable blockchain that employs chameleon hashing (cf. https://eprint.iacr.org/2016/757.pdf). We are looking now for implementations ...
0
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1answer
34 views

Why does ed25519 seem to accept and use 96-byte / 384-bit signatures?

Why do ed25519 signature verify functions accept 96-byte signatures? Take this piece of code for one example: crypto_sign_ed25519_open() requires that signatures be ...
15
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2answers
3k views

A website that identifies an RNG from its output

This happened during a discussion of RNG entropy, and the difficulty of verifying the level of entropy in a long sequence of bits (e.g. a private key.) A colleague of mine told me about a website ...
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0answers
29 views

How Unstructured data are encrypted?

In general , data are structured and unstructured. In short, how actually unstructured data are encrypted ?
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2answers
68 views

All generators for modulo p

so I have to find all generators for modulo p. And I thought: isn't there are rule for it? As far as I remember, every number from {1,...,p-1} is a generator because p is a prime. Is that true? Or am ...
2
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1answer
36 views

CSPRNG Unique Seeds

Are there conditions on the definition of cryptographically secure pseudo random number generators that require distinct seeds to generate distinct (periodic) sequences? What if a generator has the ...
-1
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0answers
23 views

Accidently deleted “~/.gnupg/pubring.kbx” , how to recover keys [migrated]

is there is any way to recover the encryption keys in this case, since they really important 1) the issue: i've lost my gpg key identifiers by deleting ...
0
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1answer
31 views

security parameter in lattice cryptography

In paper Lattice Signatures Without Trapdoors(Lyubashevsky2012), $n$ is the security parameter, why the authors set $n$ as 512 but not 80/100/112 to get 80-bit security/100-bit/112-bit security?
1
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2answers
87 views

Can an AES-GCM be cracked if the key is known but the nonce isn't?

I'm kind of new in this field and I've been trying to learn it. I'm now facing an issue where I have a couple of packages encrypted with AES-128 GCM and I have the key that was used to encrypt these ...
1
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2answers
55 views

How to backup a secret encrypted by multi parties without revealing the secret?

I'm searching for a way to backup a secret that only the end user knows the information with 2 trusted hosts. But trusted hosts shouldn't have access to secret at any time. First basic version : ...
0
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1answer
63 views

Can there be more than one valid private exponent for a given p, q, and e in RSA encryption?

For example, given: p = 173, q = 149, e = 3 Using phi(n) gives d = 16971 While using lambda(n) gives d = 4243 Both values satisfy the checking equation (de)%phi=1, so are both correct, and if so, ...
1
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1answer
45 views

How does re-hashing affects security strength?

I am currently saving hashed passwords for my website. Passwords are salted and then hashed using SHA3-512. I understand the security level of SHA3-512, as it is for all Keccak algorithms, is half the ...
1
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2answers
60 views

Anonymous location hashing

Is it possible to know if two geographic locations are within a certain distance of each other without revealing the location? I'm thinking about contact tracing during the COVID-19 outbreak. ...
-2
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0answers
103 views

why after saving File becomes larger? Steganography [closed]

274534d7d1780203956040e16a2fd8712e21596c92d7ac2ecd959d0166f8a501 I am trying to solve this puzzle. Source program is unknown. However after saving the file from editor it becomes larger than original....
4
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3answers
949 views

Why do people criticize and mistrust the e-voting based block chain?

I am planning to implement an e-voting system based on hyperledger fabric blockchain, however, I came across many criticisms from well-known security experts like Josh Benaloh and others. The problem ...

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