# All Questions

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### how to change math.random() implemented in javascript to securerandom [closed]

In Javscript code in one of our application,I am trying to change Math.random to secure random.I am not sure ,how to change.can anybody help?
139 views

### Which crytographic standard were RC5, CAST5 and Blowfish based on? [closed]

Which crytographic standard were RC5, CAST5 and Blowfish based on? A. AES B. RC2 C. 3DES D. DES
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### Finding Private Key $d$ using RSA [duplicate]

I'm a RSA n00b when it comes to the mathematics for RSA. After spending some time reading, watching lectures, etc. I pretty much have everything down, except for how to figure out the equation for ...
21 views

### TPM specification physical presence requirements

I am looking at TPM Main-Part 1 Design Principles_v1.2_rev116_01032011 and on page 69 of pdf, equivalent to page 57 of the document itself,there is comment on physical presence as follows: "Observe, ...
23 views

### change in bits leads to change in rounds the reason? [duplicate]

In AES algorithm why there are 10 rounds for 128 bits whats the reason behind it like we have in raid storage technology or something else
42 views

### Keys and key-stretching when authenticating requests?

I'm making a REST application and still a bit confused about this issue. basically, to authenticate incoming requests, I give out userId, issued timestamp, expiry timestamp (normally 3 months after ...
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### How secure is 'Plain Old RSA' [duplicate]

Let's say I use RSA encryption, it's 2048 bits and I use a simple character padding scheme, every character is turned into a 3 digit number and strung together, then encrypted. Saying that no message ...
31 views

### What is the shortest fingerprint of a Curve25519 public key that is secure [duplicate]

My clients have to exchange public keys. To ensure security they are exchanging fingerprints and typing them into the computer by hands. I want the fingerprints to be as short as possible. I am ...
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### RSA incorrectly translates for small keys [duplicate]

I've been learning about RSA and wrote my own implementation. I don't pretend to have intuitive understanding of RSA or that I understand why it works, but I believe to have some basic understanding ...
38 views

### How to apply linear cryptanalysis to PRESENT?

Can someone help me implement linear cryptanalysis of the PRESENT block cipher? How should I start with 64 bits of plaintext and 80 bits of key?
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### Generating keys in RSA [duplicate]

I'm trying to learn how RSA works. From what I found online, I'm supposed to generate private key using Extended Euclidean algorithm. I've managed to generate the public key, but don't know how to ...
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### 802.1X Radius WLAN protected by certificate 1024-bit key

I want to ask you a question. I have WPA-2 (enterprise) network. Also called as 802.1x. I use the Linux Zeroshell distribution, which is optimized for these services. Linux Zeroshell is provides a ...
34 views

### What do you mean by Ciphertext indistinguishability [duplicate]

Wiki definition : A cryptosystem is considered secure in terms of indistinguishability if no adversary, given an encryption of a message randomly chosen from a two-element message space ...
36 views

### Is it possible to re-generate ECPublic key from raw private key and curve params?

As per my understanding, in Elliptical curve cryptography, the EC PrivateKey is nothing but a bigInteger value. If you know the curve specs and you have this private BigInteger value (which I am ...
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### Simple RSA Key Generation example [duplicate]

I have two prime numbers: p = 37 q = 41 And I need to find whether any of these prime numbers, 5, 7 or 11, can be used as a valid encryption key e? My working ...
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### AES-GCM Hash sub key parameter in Intel's IPsec library

I am trying to use Intel's optimized AES-128-GCM implementation (from the Intel white paper “Fast Multi-buffer IPsec Implementations on Intel Architecture Processors”, you can find the code here). ...
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### Is there a fast implementation of RSA for Microcontrollers?

Zhe Liu, Johann Großschädl, and Ilya Kizhvatov. "Efficient and Side-Channel Resistant RSA Implementation for 8-bit AVR Microcontrollers" describes a fast implementation, but only contains a sketch of ...
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### Applying Vigenere on small strings with sorting capability

I am new to cryptography and have a question about a use of Vigenere cipher in the case of small strings. I'd like to encrypt keywords that are smaller than 10 characters. If I use Vigenere ...
33 views

### Clarification on the state of the art of qubit commitment

What is the current state of research on quibit commitment? It seems that the answer is not 2001 but it seems to me that a lot of these pdf are referring to a old protocols of quantum bit commitment ...
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### A standard extension of ECIES for multiple recipients (broadcast / multiparty)?

I have one sender, and a small number (~5) of recipients. The sender knows each recipient's public EC key. I want the sender to broadcast a single message in such a way that any one of the recipients ...
33 views

### cumulative secrets

Imagine a server with an authentication scheme that utilizes an element of randomness in new sessions (i.e. one that uses the secure remote password protocol). At the end of a successful ...
56 views

### key exchange using hashing with preshared secret

I came upon an idea the other day that I had some questions about. I am not a security professional but I do study with an amateur interest and have not heard of this particular idea before. There ...
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### Does OEAP padding limit the size of my modulous to the size fo the hash function?

im looking at wiki at the moment as how to use oeap padding and it appears, help me out if im wrong as G(r) - expands r to the size of the padded message, I am then limited by the size of my hash ...
68 views

### Cryptographic operations for NISTP256 can be implemented using montgomery method?

I need to implement cryptographic operations starting with the curve NISTP256. I have been told to implement it using Montgomery method. I read a pfd from http://saluc.engr.uconn.edu/refs/sidechannel/...
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### Edwards / Montgomery ECC over binary extension fields

I recentely had a discussion about the redesign of our ECC code for the library I'm collaborating on and the person I was discussing with came up with Edwards and Montgomery curves over binary ...
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### Does the RSA algorithm use repeated squaring?

Simple question: in order to reduce such huge exponents in modular arithmetic, is repeated squaring used in RSA or is there a better way to implement it?
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### Why are the first 4-6 characters from ssh-keygen (RSA) the same everytime? [duplicate]

New to StackExchange, so please bear with the newbie. At my current job we are often creating many ssh keys with ssh-keygen (RSA). One thing I have noticed is that the first few characters (say the ...
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### How to check the signature without the predetermined function in ECDSA from openssl?

I'm developing a client for a two-factor authentication in Qt/C++ under openSUSE 13.2, 64bit. I've got the FIDO U2F Security Key from yubico/fido. I'm using the classes from openssl, in particular <...
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### Does CP-ABE have any disincentive to share secret keys

I want to use a CP-ABE scheme to encrypt data to be accessed by multiple unknown (at time of encryption) users. Reading the papers related to CP-ABE, there does not appear to be any disincentive for ...
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### How to find the integer multiplicand from given two points?

I have two points on an elliptic curve $P(x_1,y_1)$ and $Q(x_2,y_2)$ and a scalar value $x$, where $P=x \cdot Q$. What is the best way that I could figure out the value of $x$? Given that I know all ...
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### How do we measure number of possible encryptions in One Time Pad [duplicate]

trying to brute force a specific length of ciphered pad, how do we measure the total number of possible encryptions in One Time Pad
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### Is this ECC based messaging method secure?

I developing an encrypted messaging for ZeroNet (aP2P file-based network, website: zeronet.io) and would like to have some guidelines if any of this could work. My first idea: In ZeroNet every user ...
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I've read the following paper and have one question on it. M. Luby and J. Staddon, "Combinatorial Bounds for Broadcast Encryption", EUROCRYPT'98. On page 523 (12th page of the paper) the authors say ...