Testimonials

Dear Sir,

Came across your web site some time ago when I was dithering over what CDs to put in my 12-CD cassette in my car. In those days I had in excess of 500 CDs, and could never make up my mind which ones to listen to. I was tending to put just my favourites in week after week. I googled ‘Random Number,’ and your site was the result. I have now well over 700 CDs and religously put in the CDs that the number generator commands.

Thanks for the service.

—Malcolm Lashbrook

I discovered Random.org due to the New York Times article on random numbers today. I've already downloaded the three pre-packaged 10 MB files and wish there were more of them (at least three more 10 MB files). I'm using them as audio—interpreted as 16-bit WAV files, they form perfect white noise, which has many uses in acoustics and audio-equipment testing, which is my field. Used in pairs, they form perfect, uncorrelated stereo white noise.

I've been able to get more use out of the first three 10 MB files by reversing their byte order (the resulting white noise sounds the same) and by using various other audio-editing tricks like concatenating the files to produce long streams). I've also used 1, 2, 3 or 4 bytes at a time to produce different audio wordlengths. Thanks to the 2's complement number system, this latter scheme is particularly effective for audio since you always get equal distributions of data points above and below zero.

Your files produce better noise than some pseudo-random schemes I've tried, since the latter can produce an audibly detectable cyclic effects in the sound quality if the sequence length is too short. The ear is an extremely good detector of such patterns. A quick-and-dirty one-time-pad scheme would involve Xor-ing your random bytes with the lower bytes of each 16-bit word on a commercial audio CD to produce the random number table. The recipient would only need your file and another copy of the audio CD. To crack it you'd have to search through every data sample on every CD ever released!

—David Ranada, Technical Editor, Sound & Vision Magazine