# Skewed Randomness

According to random.org,

Any source of true randomness may contain skew towards 0 or 1 in the data

I am a bit confused about what this exactly means and why this "skew" is present in all "true random" data. Does this skew risk the integrity of some values that would otherwise be seen as cryptographically secure? Does it really matter much?

Thanks a lot in advance for any responses. All are greatly appreciated!

• next time, please provide links to the source of quotes Commented Oct 21, 2015 at 4:23

EDIT: Schroeder pointed out that I've mis-read the quote (due to lack of context). This is a corrected answer

The full quote is this

The graphs on this page gives an indication of how good the raw random data used by RANDOM.ORG is. Any source of raw randomness may be biased (skewed) towards 0 or 1, meaning that more 0s occur in the data than 1s or vice versa. An important part of generating true random numbers is to perform skew correction on the raw random data, i.e., remove any such skew. The graphs on this page show how close to unskewed the raw random data used by RANDOM.ORG is. If this data is perfectly unskewed, even before process, you will see a purity rating close to 100%. If there is skew in the data, you will see a lower rating. However, even if the raw data is skewed, the skew correction algorithm will correct it, and the skew will not appear in the processed data.

The first sentence

Any source of true randomness may contain skew towards 0 or 1 in the data

means that isn't a 'fair' RNG, which has equal probabilities for both outcomes. Instead, it's sometimes more likely to produce one number than another.

This does not affect the final generated data, because

However, even if the raw data is skewed, the skew correction algorithm will correct it, and the skew will not appear in the processed data.

So the data RANDOM.org presents to you is unskewed.