Take the 2-minute tour ×
Cryptography Stack Exchange is a question and answer site for software developers, mathematicians and others interested in cryptography. It's 100% free, no registration required.

This question already has an answer here:

I am thinking of buying a USB hardware advertised as producing a stream of 'high quality' random numbers which I take to mean they are indistinguishable from a stream of 'true' random numbers. If I add (or XOR) such a 'high quality' stream with a stream of PRN's from my computer, will I still have a 'high quality' stream?

share|improve this question

marked as duplicate by otus, e-sushi, Gilles, rath, poncho 9 hours ago

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Do you have a specific reason for wanting to do this? –  mikeazo 17 hours ago
add comment

1 Answer

Provided that the two streams are independent and you use XOR to mix them, then yes, you can't degrade the higher entropy source even if you XOR it with constant data (i.e. all 1).

See the answer to this question for proof.

share|improve this answer
This looks more like a comment than an answer. All you did was rewording the first line of this answer and linking to the question of which this question is already commented to be a duplicate. If your post isn’t meant to be interpreted as a comment or a link-only answer, you might want to add some details that actually show personal effort… like providing your own, additional proof for example. –  e-sushi 17 hours ago
add comment

Not the answer you're looking for? Browse other questions tagged or ask your own question.