Testimonials

In several things that I do, I require some form of randomness (for example, secure primary keys for databases, with almost no chance of collision error). To do this, I use your site to create them. A simple generation of numbers between 0 and 35, and then change them into their base-36 equivalent, however long the sequence needs to be, and you have an virtually unguessable primary key sequence. You can’t guess what the next key in the sequence will be. Very useful for keeping people from being able to hack your customer list and finding out who does business with you (they might be able to guess one, but the next won’t be sequential, so they would have to start all over again to find the next). I also use it in my writing, to generate datasets for locations and people by assigning integers to various items and using the site to pick the ones that apply.

—John Anderson

I study the life-cycle of viruses, and I perform lots of tissue culture experiments. In order to try to develop theories to explain some results I was getting, I wrote a computer program that uses a Monte Carlo scheme to simulate infection of cells by viruses. I need a different random number for each simulated virus, in order to randomly assign it to a cell that it ‘infects.’ In order for the results to be meaningful, I need to simulate tens of thousands of ‘cells’ and hundreds of thousands of ‘viruses,’ so I need hundreds of thousands of random numbers. The pseudo-random numbers produced by the Apple Macintosh built-in linear congruental generator proved themselves to be not good enough for the job, as I found that some numbers were chosen too often, a definite no-no for my purposes. Then I saw the NY Times article about this site and gave it a try. First I tried using Random.org numbers to seed the Macintosh generator at frequent intervals during the execution of the simulation, but it did not solve the problem. So I tested using all numbers from this site and they passed my quality test. So now I download several batches at a time of 10,000 numbers between 1 and 40,000 and string them into big files as the sources of my numbers. I'd like to be able to download them in even bigger batches, though. Thanks for a truly useful service!

—David N. Levy, University of Alabama at Birmingham