creation of (real or pseudo) random numbers (or bits).

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True Random Number Generator by milliseconds per keystroke (TRNG-Kms)

The simplest way to generate truly random numbers for OTP keys is to measure the time in milliseconds between each keystroke on a keyboard. The randomness depends on the user typing in various speeds. ...
2
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1answer
55 views

Is my implementation of a PRG at least intuitively secure?

I've devised a PRG using Bezier curves , constructed with Bernstein polynomials, and I was wondering if you guys could help me with some suggestions or constructive criticism. Basicly I take a random ...
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2answers
816 views

Is it safe to seed a random number generator from system time?

It seemed to me that the Bouncy Castle SecureRandom class for C#/.NET only uses DateTime.Now.Ticks as its seed by default. I ...
2
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2answers
74 views

Collecting entropy: can I use timing of reading as a separate source from the reading itself?

I'm implementing an entropy gathering program. For that I collect 2 bits from two gpio-pins connected to a random source. I whiten this stream of bits using the von Neumann decorrelation algorithm. ...
2
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1answer
49 views

mixing two asymmetrical random number generator streams

Knuth describes in "the art of computer programming part 2" an algorithm called "M" for mixing two streams of random numbers. This can be used to mix random number streams giving the assurance that ...
5
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1answer
74 views

How to construct a next bit predictor from a distinguisher

I read the claim, without proof, that it is possible to construct a next bit predictor for any PRNG given an oracle distinguisher for that PRNG and vice versa. How do I prove that? A distinguisher ...
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0answers
69 views

If I add a stream of true and pseudo random numbers, do I get another stream of true random numbers? [duplicate]

I am thinking of buying a USB hardware advertised as producing a stream of 'high quality' random numbers which I take to mean they are indistinguishable from a stream of 'true' random numbers. If I ...
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0answers
55 views

Determining if a stream of bits is statistically random [duplicate]

Suppose I would like to build a hardware RNG. The details aren't important but let's say I've found a way to generate theoretically random bits, and I want to test to see if they are in fact "random ...
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1answer
260 views

Random Number Generator based on AES CTR

I've just about done tinkering with an open source DRBG, and I sure would appreciate a bit of advice from this community. Here's the link to the project, hosted at codeproject.com. It is written in ...
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1answer
77 views

How does Web Cryptography API produce secure PRNG?

How does Web Cryptography API (eg window.crypto.getRandomValues) produce secure PRNG? Specifications: https://dvcs.w3.org/hg/webcrypto-api/raw-file/tip/spec/Overview.html#RandomSource-interface ...
2
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1answer
90 views

Is it possible to get better randomness by using multiple PRNGs?

I don't know if this question even makes sense, but: Is there be any benefit or impact to some sort of hierarchical (e.g. a PRNG drives the decision for which PRN to pull from a set of PRNGs) or ...
2
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1answer
48 views

LFSR Output Sampling for Berlekamp-Massey

Looking at the use of Linear Feedback Shift Registers in cryptographic algorithms, I have learned that the Berlekamp-Massey algorithm can be used to find the (shortest) LFSR that generates a given ...
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1answer
287 views

Fastest random number generator

I just read High performance physical random number generator by K.H. Tsoi, K.H. Leung and P.H.W. Leong. It proposes a physical RNG of speed 400 Mbps. Is this the fastest random number generator at ...
2
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1answer
51 views

Is there a deterministic number generator that allows me to share some (not all) numbers I've generated using a smallish seed?

I was just wondering, is there a type of deterministic number generator that allows me to share some (not all) numbers I've generated using a smallish seed? I have pairs of random numbers and need to ...
8
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2answers
186 views

Trial divisions before Miller-Rabin checks?

I'm trying to understand prime number generation (more correctly, the primality checking) as described in Handbook of Applied Cryptography. The context is circa pages 145 - 150, and specifically ...
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1answer
119 views

Mixing Entropy Sources by XOR?

Assume that I have two sources of entropy (say, a hardware RNG and a CSPRNG) and that the two sources are independent (do not know anything about the internal state of the other RNG). Can I mix them ...
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1answer
50 views

How exactly are PRNG's used to encrypt material, and what makes one any more secure than the other?

I hope my question isn't as lazy as the title indicates. What I want to ask is how people literally integrate a PRNG with encrypting material. I wrote a silly little script in Python a while back ...
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0answers
50 views

Special random distribution algorithm

I am implementing ring signatures as a part of an authorization system. Since the number of users could get high enough to make computation on end-user devices infeasible, I am thinking of ...
4
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1answer
115 views

Generating unsigned, bounded random value using signed bounded random values

Use case: I have a random number generator that can generate random numbers in a range that is limited by a number $x$, say $x$ ranges from $2$ to $2^{(n - 1)} - 1$ exclusive. In this case $n$ is ...
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3answers
154 views

How do I produce a stream of secure random numbers from AES-Counter mode?

I have just made my own program to encipher, using AES in counter mode, and have validated it using NIST data. So I know I have done it properly. I have read that AES-CTR can produce a stream of ...
0
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1answer
91 views

How can I generate a brief (100) stream of random numbers, not using the computer or throwing dice? [closed]

I am looking for a method of making random numbers that is off-line and is also independent of specialist equipment like a Geiger counter.
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3answers
274 views

How vulnerable is the C rand() in public cryptography protocols?

I just learned about the basics of public cryptography a few weeks ago and I am curious as to why the C rand() function should not be used for crypto schemes. For example, say I want to generate a ...
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1answer
46 views

What's wrong with this “order-preserving MAC” function?

Please note: this is purely a thought experiment and not intended for any real-world usage! I came up with a simple function $\mathrm{OPF}$ to map the integers $[0,C)$ (where $C$ is the "ChunkSize") ...
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2answers
135 views

Why are Fortuna entropy pools reset after a reseed?

I've implemented LibTomCrypt's version of fortuna and am wondering about the pool resetting after a reseed. In fortuna.c in libtomcrypt we have the following (which is that part that adds the entropy ...
4
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1answer
211 views

Secure AES Key Generation via Salsa20?

I am not creating my own cryptography or anything, but to learn about the Dos and Donts of cryptography, I am looking into AES encryption and ways to generate keys for that. As far as I've ...
2
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1answer
127 views

LFSR get output from characteristic polynomial?

Say you have a characteristic polynomial of an LFSR: $$f(X) = X^4 + X^3 + 1$$ How can I use this function f to get the output of the LFSR, given some initial state? Obviously I can create the LFSR ...
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3answers
183 views

How useful is NIST's Randomness Beacon for cryptographic use?

NIST have just launched a new service called the NSANIST Randomness Beacon. It has been met with some initial skepticism. Perhaps the cryptography community would have used it before June 2013 when ...
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2answers
258 views

Randomness test question from FIPS 140-1 and comparison with 140-2

In FIPS 140-1 there are 4 statistical random number generator tests (The Monobit Test, The Poker Test, The Runs Test and The Long Runs Test. Then FIPS 140-2 came along and supposedly tightened the ...
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1answer
75 views

Reseeding a PRNG with the generated PRN

Would reseeding a PRNG with the PRN from the previous generation have any effects whatsoever on the quality of the generated numbers; if so, does this depend on the PRNG used, or are the effects ...
3
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1answer
126 views

Unpredictability vs randomness

I'm experimenting with creating an entropy source for an environment where I have no hardware available and the language is very high level (executed in a virtual machine). I know it's not a good idea ...
3
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0answers
118 views

Entropy of Androids motion-sensor data

My app on Android uses the built-in motion sensors to collect seed-data for the PRNG (java.security.SecureRandom) that is later to be used for key-generation. The user is told to shake the device so ...
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2answers
95 views

Is it possible to calculate the 'skeleton key' for DUAL_EC_DRBG? What would it take?

According to Bruce Schneier the constants used in the spec of DUAL_EC_DRBG may be related to a secret set of numbers, that could function as a master key for ...
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1answer
66 views

If $G'(s)=G(s0^{|s|})$ and $G$ is a PRNG, is $G'$ necessarily a PRNG? [closed]

I argue it is because there should be no more correlation between the outputs $G(s0^{|s|})$ than between the outputs $G(s)$. Thus we can say the $G'(s)$ is a PRNG that satisfies $|G'(s)| \geq 4|s|$. ...
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37 views

Determine the iteration times using Pollard's rho Method for factoring

Let's say, we have a large number $n=181937053$ and $f(x)=x^2+1$. And also we know that $n=12391 \times 14683$. The problem is that ,using Pollard rho method, can we find the algorithm iteration ...
2
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1answer
102 views

Detecting steganography in the stream of short messages

I have stream of millions of short n-bit (n<30) messages generated by some random number generator. The source of random number generator is not available to me. I suspect there are messages used ...
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2answers
111 views

Standard or guidance for entropy collection

I need to write some high-level security requirements which include a random number generator suitable for use in cryptography. I don't need something very formal, this isn't a security certification ...
2
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2answers
154 views

Seed / reseed DRBG too often?

There are limits to how much you can use a the DRBG before you have to reseed it, but are there any limits to how much you must use it before reseeding? Take the following scenarios as an example… ...
2
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1answer
173 views

Predicting Java's PRNG using partial output

I have a program (a game) that uses Java's nextInt function with parameter 0x10000 to get a random 16-bit number. Java's ...
2
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1answer
115 views

Does changing the random number selected for each message increase security in Schnorr's scheme?

I was reading about Schnorr's scheme and in that for signing the signer generates a random number and continues with his operation. I am trying to implement this in a scenario where the signature ...
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2answers
267 views

Breaking a PRNG Scheme

Assume the following scheme for a PRNG generating decimals in [0,100) Given a message and a key, compute tag := HMAC512(message, key). Take the first 5 hexadecimal characters of the tag. If the ...
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1answer
374 views

How can i predict the next number of a long sequence of seemingly random numbers? [closed]

How can I accurately predict the next random number between 1 and 999, given past results. I have no knowledge of the PRNG or algorithm used. How can I predict the next number of a long sequence of ...
0
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1answer
91 views

Oracle DBMS_RANDOM algorithm?

Oracle DBMS offer builtin random number generator (pseudo to be accurate). DBMS_RANDOM is one of the available packages, it is however considered as insecure for cryptography. Do we happen to know the ...
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72 views

Is allowing a user to specify a Curve25519 signing key secure?

The cryptocurrency Nextcoin has users create Curve25519 signing keys with a minimum length of 70 characters. Is that secure? Would it be better to use a random number generator? Is it possible to ...
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2answers
199 views

Are the SHA family hash outputs practically random?

Say I hashed the output from a random number generator (with nonce), would the resulting SHA256 hash be as random as the inputted number? And If I used the first 5 hex characters, and then used the ...
1
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1answer
96 views

Trustless, Multiparty Random Number Generation

I've been having trouble with coming up with a random number generator that produces a random number between two parties. My current scheme is this: User 1 gives user 2 the hash of their randomly ...
2
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1answer
97 views

Would data be secure if a cryptographically secure PRNG was used for encryption?

For example, say you have a client and server. You use asymmetric encryption to securely deliver two seeds from server to client. Each user then seeds two PRNGs (one for incoming data, one for ...
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1answer
302 views

Can a LFSR be cryptographically secure?

I have been looking at an embedded microcontroller which has a cryptographic hardware engine (in particular the PIC32MZ family). These devices have what they advertise as a cryptographically secure ...
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3answers
202 views

Deterministically combine more than one source of entropy

What is the proper/canonical way to do this? For example, $0 < r1 < 1$ and $0 < r2 < 1$. Presuming uniformly distributed probabilities for the two, combining/averaging them is going to ...
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191 views

Random Number Generation with a Entropy pool versus Seed

To give a little background I'm currently implementing a crypto library in JavaScript. I have started porting across Linux's random number generator because its both publicly scrutinized, it is ...
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1answer
499 views

Good entropy source for generating openssl keys

I need to generate a CA (4096-bit RSA) and server keys for openvpn and I want them to be "top quality". Here is my plan: gather entropy from multiple sources (saving individual files): FreeBSD ...