What is the difference between a randomly generated number and a safe randomly generated number?

Question

As the title says. What is the difference between a randomly generated number and a safe randomly generated number?

Answer 1

No computationally valid algorithm should:

• restore the seed, or
• predict "next bit"

for a safe random number generator.

Example: a linear feedback shift register produces many random numbers, but with sufficient output, a seed can be detected and all subsequent numbers will be predicted.

Answer 2

A safe random number does not have to be predictable even with a list of previously generated random numbers. Usually you used it as a key to the encryption procedure, so you would not want it to be guessed or predictable. Of course, the guess depends on the context, but you must assume that the attacker knows everything that you know, and can use it to create your random number.

There are various websites that generate secure random numbers, one trusted hotbits . If you only do random number generation as a one-time action, why not use the result of the lottery, as it is random. Of course, don't tell anyone which lottery and which they are drawing, and put these numbers through the appropriate mahjong to get the range you need.

Answer 3

Please note that the numbers are not random. “Randomness" is simply not a property of any given number (even if XKCD says otherwise).

Only the process of generating numbers can be rated as "randomness." Read What color are your bits to discuss this topic.

Answer 4

Only with a "random number" is usually implied a pseudo-random number. Since this is a pseudo-random number, it can be (easily) predicted by an attacker.

A safe random number is a random number from a truly random data source, i.e. involving some kind of entropy pool.

Answer 5

Agree with Purfiedeas. There is also a good article on what is called Cheat Online Poker.

Answer 6

A random number probably means a pseudo-random number returned by the "seed" algorithm.

A safe random number will be the true random number returned from the device, such as a cesium-based random number generator (which uses the cesium decay rate to return numbers). This naturally occurs and cannot be predicted.

Answer 7

It probably depends on the context, but when you compare them, I would say that the "random number" is the random number pseduo and the "safe random number" is really random. The first gives you a number based on the seed and the algorithm, and the other on some random random function.

Answer 8

This is similar to the difference between AES and ROT13.

To be less frivolous, there is usually a tradeoff in generating random numbers between how heavy it is and how predictable the next in the sequence is when you saw a few. The random number returned by your language built-in rand () will usually be a cheap, predictable sort.