1
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0answers
29 views

Data in frequency modulated audio [closed]

I'd like to have a peek at the firmware of a piece of Hardware. Its firmware is available as a .wav file to be uploaded via audio jack. https://drive.google.com/open?id=0B6S_PcWWM1YlQnNwT2FSMnFzVE0 ...
1
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0answers
27 views

ephemeral-ephemeral ECDH and MITM attack [duplicate]

ephemeral-ephemeral ECDH is it susceptible to MITM attack ? if yes, can you please give me a detailed answer ( Workflow that can be followed by the attacker) and how we can prevent this attack ...
1
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0answers
31 views

Why the group order has to be prime for pairing-based cryptography [duplicate]

I'm trying to get into pairing-based cryptography and I don't see why the group order of the group G in the pairing function e:G*G-> G_t has to be a prime number. I don't find an argument why ...
1
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0answers
78 views

Encrypting a 160-bit plaintext into a 160 bit ciphertext with a 128-bit Block Cipher [closed]

So I have a kind of interesting issue. I have a field in my data store which must take exactly 160 bits of information. Some users will choose to make this data encrypted, some won't, so some of those ...
1
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0answers
40 views

PKCS#11 Sessions

I am maintaining an application that uses PKCS#11 to talk to a smartcard. Somehow a session gets generated, but i cant figure out where in the code. I am using c# and the PKCS11Interop wrapper. The ...
1
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0answers
67 views

Powerline password conversion [closed]

I read this post from Ben Tasker describing how to take control of a powerline network. Since I am interested in security, I tried to do the same thing, to see if it was possible. I used Devolo ...
1
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0answers
36 views

Is it possbile to get same set of public and private keys twice while creating CSR ? If so where does the conflict happens !?

I'm new to cryptography and please clarify if my below assumption is wrong. Lets assume, that two different banks creating CSR and they get identical public and private key pairs of RSA. In such ...
1
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0answers
137 views

Is there specific name for simple XOR with ADD/SUB encoding?

Several years ago a group of malware authors began using code like this: for (j = 0; j < length; j++) ptr[j] = (ptr[j] ^ VALUEA) - VALUEB; for encoding, and ...
1
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0answers
43 views

research on Encryption for master [closed]

I'm tring to choose an way for an Encryption mothod for my research? So,I want to choose one-layer encryption or multilayer encryption,and I want it to be easy to applicable. when I search about it, ...
1
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0answers
40 views

Are there any existing ASN.1 structures for transferring symmetric keys?

Is there any reasonable ASN.1 standard to encode symmetric keys? I found PSKC, but it seems extremely heavy, and I can't quite find any library (e.g. bouncycastle) that would simplify using it. If ...
1
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0answers
36 views

If I know the hash function that produced a hash key, how easily can I generate an input to hash to the same key? [duplicate]

The title is pretty descriptive of my question. As an example, say I use the MD5 hash function to create a hash key of the word "hello": 5d41402abc4b2a76b9719d911017c592. There are two questions I ...
1
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0answers
23 views

LFSR, different bits from different initial states

Suppose we useLFSR, which gives output $x_1x_2x_3\dots$ from some particular initial state. From another state, different from previous, same LSFR though, it gives sequence $y_1y_2y_3\dots$ ...
1
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0answers
27 views

If you were to design a PKI from scratch, what would you do? [closed]

In what ways would you simplify? What would be changed to be more modern or extensible? Suppose you have no requirement to adapt to previous protocols. Links to proposed designs, existing ...
1
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0answers
39 views

Symmetric stream cipher, is it known?

I am thinking on a simple symmetric stream cipher. My first idea is the following: The key is a set of array of random bytes ($\underline{k}_1$ ... $\underline{k}_n$), whose length is $l_1$, $l_2$, ...
1
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0answers
30 views

Where can I find a versatile PKI and library leveraging curve25519?

I note that Things that use Curve25519 provides a long list of protocols, software, and libraries that leverage curve25519, but I'm wondering if there is any such software that more fully implements a ...
1
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0answers
22 views

Is there a system where I can securely store a secret value and compare a semi-ambiguous input to it?

I have an idea for a new kind of mobile phone lock screen. When you first create your pattern, you put together a series of colors and compass directions from the following choices: Red, Blue, Yellow, ...
1
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0answers
54 views

2 round GOST_28147-89 cipher distinguisher

So, here is the scheme of how this will look graphically: The deal is to present distinguisher for this cipher. First of all here is my drafts: Way 1 Assume that distinguisher displays in ...
1
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0answers
561 views

Decrypt using OpenSSL produces packing errors

I am receiving an encrypted file and it's key from a partner. The Key has itself been encrypted using our Digital Certificate Public Key, though I don't know exactly how. The partner has instructed me ...
1
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0answers
43 views

What is the hardness in Decisional Linear Assumption (DLIN)?

I had understood what does the DLIN assumption means and here is a related question. But I fail to understand the 'real hardness' in this problem. I would be grateful if someone can help me to ...
1
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0answers
44 views

Attribute Based Encryption [duplicate]

Could someone explain the main differences between Key Policy Attribute Based Encryption (KP-ABE) and Ciphertext Policy Attribute Based Encryption using an example? I know that KP-ABE depends on the ...
1
vote
0answers
207 views

How do I create a PKCS#7 or CMS SignedData in python? [closed]

There doesn't appear to be PKCS#7 or CMS support in pyCrypto. I'd appreciate a recommendation on a Python library wth CMS / PKCS#7 support. Ideally, there will be a call that will create return ...
1
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0answers
33 views

Open source code about the basic Quisquater-Piret DFA of AES-128 [closed]

Where can i find open source code about the basic Quisquater-Piret DFA of AES-128? Are there any websites sharing the code about such physical attacks?
1
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0answers
49 views

Concepts for realization in applied cryptography [closed]

I'm a computer science student (not a mathematican) and I'm gonna to write a master degree diploma on applied cryptography. Specifically, I'd like to create a realization of some cryptographic stuff ...
1
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0answers
16 views

Is there any equivalent to the apache xml security library for JSON? [closed]

I'm talking about org.apache.xml.security(santurio) Is there any equivalent library that works with JSON and provides the same set of features? (mostly AES-128 with KEK support)
1
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0answers
63 views

In DGHV FHE, why noise $r$ can be in $(-2^{\rho'}, 0)$?

"Fully Homomorphic Encryption over the Integer" described a simple FHE scheme based on the GACD assumption. Its encryption function (on page 6) has the form $c \leftarrow (m + 2r + 2*\sum_{i \in S} ...
1
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0answers
88 views

CPA-security proof of “l-padded RSA” encryption scheme

The 10.9 exercise from the Katz-Lindell textbook creates a lot of confusion, let me state it here. Consider the following experiment for an algorithm $A$ and a function $l$ with $l(n) \leq 2n-2$ for ...
1
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0answers
20 views

Encipher the following plaintext message using the Vignere method using the key K = [4,2,3] [closed]

Encipher the following plaintext message, Exotic, using the Vignere method using the key K = [4,2,3] Can anyone help me get the ...
1
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0answers
61 views

Ciphertext size of any CPA-secure public-key encryption scheme

I know that, for any CPA-secure public-key encryption scheme, the size of the ciphertext after encrypting a single bit is superlogarithmic in the security parameter. That is, for $(pk,sk) \leftarrow ...
1
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0answers
38 views

Email: Degrees of Security [closed]

It has been explained to me by IT that there is no such thing as totally secure email - but rather a spectrum. If systems are secured via https and SSL what degree of encryption/security are we ...
1
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1answer
57 views

Why an upside down path on the evaluation of branching program on encrypted data?

Suggested by Ricky Demer in this post, I am reading the paper "Evaluating Branching Programs on Encrypted Data"(TCC 2007), which uses one-round strong OT protocol to implement homomorphic evaluation ...
1
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1answer
127 views

Modular reduction for NIST prime P256— understanding the data

I am working on a project where I need to implement elliptic curve cryptography, I am struggling from a long time in order to understand the working and the process. Modular finite field arithmetic, ...
1
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0answers
78 views

Why is there no 'ECDSA' version of 'DHE-RSA-CHACHA20-POLY1305'?

So I was just checking my TLS cipherlist and noticed that there was a 'DSS' / DSA / ECDSA version of every ...
1
vote
1answer
109 views

variant of Diffie–Hellman key exchange protocol

Motivation Consider the following variant of Diffie-Hellman key exchange protocol for two parties: Assume Alice and Bob share $\mathbb{G}$ of order $q$ generated by $g$ Alice samples $a$ ...
1
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0answers
51 views

Details related to the ZIP algorithm used in PGP message encryption? [closed]

I am very new to PGP. PGP encryption works with hash function, asymmetric encryption, symmetric encryption and a zip algorithm (LZ77). What I know is that the zip algorithm is used to reduce the ...
1
vote
0answers
129 views

Example describing Baek and Zheng’s threshold identity-based decryption scheme

I am trying to work through an example of Baek and Zheng’s “threshold identity-based decryption scheme” and I tried a lot to solve this, but somewhere I’m doing something wrong. I hope someone can ...
1
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2answers
44 views

Validate per round rather than cycle-walking in FPE

I was thinking about FPE specifically for numbers, CC, phone, SS #, etc. and I thought of some small "optimization" that could be implemented. Can I validate the string length after each round in the ...
1
vote
1answer
38 views

Is hashing data with dynamic keys still worth effort?

some years ago it took long time to "decrypt" hashes because they took slow cpu to brute force. Nowadays they use graphic cards for stuff like this and can do this most time in less than 20 Minutes ...
1
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0answers
309 views

How to calculate the avalanche effect in aes-256?

I am a beginner in cryptography. I'm testing AES-128 bit key, AES-256 bit key, and Camellia-256 bit key. I'm using AES-256, 9 character salt, CBC mode, PKCS #5 padding, and the ciphertext using ...
1
vote
0answers
65 views

Understanding a faulty Needam-Schroeder protocol

Give this mutual-authentication protocol (along with the attack) in which Alice wants to communicate with Bob, I can't understand how the attack works. A chooses $N$ (nonce) and sends to C (trusted ...
1
vote
0answers
230 views

What are the problems of IKEv1 aggressive mode (compared to IKEv1 main mode or IKEv2)?

I would like to seek confirmation/clarification of the following statements about IKE: IKEv1 aggressive mode is supposed to be “insecure” if used with PSK. But as far as I can see, correct (or more ...
1
vote
0answers
52 views

FFX Encryption over alphabet of arbitrary radix

I understand how standard numeric FPE using a halved string in cycled Feistel networks is constructed and operates. I then read the paper regarding FFX encryption which should allow for any non-binary ...
1
vote
1answer
123 views

CP-ABE for threshold cryptography

I would like to know if there is any research work using CP-ABE for threshold cryptography? I want to know also if applying CP-ABE for threshold cryptography would overcome other techniques.
1
vote
0answers
15 views

Are there any paper/human strong crypto systems? [duplicate]

Are there any paper/human executed crypto systems that have reasonable strength? I am aware of a few candidates so far Solitare from Cryptonomicon https://en.wikipedia.org/wiki/Solitaire_(cipher) ...
1
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0answers
84 views

Prove that certain amount of data was stored

I'm looking for a way to prove that a certain amount of data was stored, through some easily verifiable piece of information. Similarly to how proof-of-work can prove through a hash that a certain ...
1
vote
0answers
50 views

What consequences do the plaintext space size has on the performances in the BGV scheme?

In the BGV paper [1], the authors say in §5.4 that you can have $\mathbb{Z}_p$ as plaintext size with a large $p$. What is the impact of the size of $p$ on the ciphertext size and computational work ...
1
vote
0answers
74 views

ElGamal signatures systems

Let $p$ prime number $q/p-1$ prime and $g\in (Z/pZ)^*$ element of order $q$.Also $a\in \{1,...,q-1\}$ the private key and $y\equiv g^a\pmod p$ the correspoding public key.For each of the following ...
1
vote
0answers
76 views

Library to find an addition chain for a large number? [closed]

I need a short addition chain for a number $n>2^{100}$ in order to implement a fast exponentiation. The memory footprint is not important. Finding an optimal chain for a large number $n$ is ...
1
vote
0answers
46 views

One-Time-Signature based codes

I'm trying to understand the sentence in bold, in the follow paragraph of A new one-time signature scheme from syndrome decoding Keygen: Given a security parameter $\lambda$, choose a suitable ...
1
vote
2answers
63 views

Pseudorandom functions: how are functions stored?

I am wondering about the setup for testing if a function family is pseudorandom. We step into a room, and query the black box with $x$, which yields $f(x)$, etc... We don't know if $f$ is a random ...
1
vote
0answers
47 views

IES: What security has the asymmetric primitive to provide?

I think most of us know the notion Shoup introduced of KEM/DEM (Key encryption material / data encryption material) which is used for example by the (famous) ECIES, where the key is the hash of some ...

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