Is it possible to draw based on the Mersenne Vortex?

Question

Law in IT

The customer needs to draw a prize, I offered him to make it based on the Mersenne vortex, he agreed, and now (there should already be a prize draw, because the action is already in full swing and the rules of the action have long been published) it turns out that this is supposedly violates the law and this algorithm falls under the concept of "random number generator", which violates the law.

It was planned to determine the winner as follows:

1. Make a selection from the database of all registered active (i.e. not banned) participants
2. Calculate the length of the resulting array using the count function to get the maximum (upper) value of the function, and the minimum (lower) value I wanted to take zero for this function, because array starts from zero
3. Pass the received numbers as arguments to the mt_rand function (this function uses the Mersenne Twirl) (I write the script in php) and eventually get a random number included in the range of these numbers
4. Extract values ​​from the array by index (I thought the index value would be the
result of step 3) it turns out the next time we run we will have n-1, where n is the number of active registered participants.

The organizer in the rules of the promotion indicated this algorithm for determining the winner.

The question is - is this algorithm of actions a violation of the law or not? And is it possible to use the algorithm described above, including the Mersen Vortex) for the draw?

PS Another small clarification, the customer does NOT have a lottery, but a stimulating promotion - these are two big differences, the lottery implies a random determination of the winner, such as pointing a finger at the sky.

Answer 1

In fact, you (the customer) can use any algorithm, the main thing is that the prize draw does not fit the concept of "lottery".
For example, "McDuck" often holds various draws-promotions, but this is not a lottery ... Look at their website for the conditions for such promotions (your customer must also have them on the website), and there must also be a "public offer" ..
Read this FEDERAL LAW ON LOTTERIES (as amended by 20 ...
And this Legal entities will no longer be able to organize lotteries // ...