[Cryptography] Finding Entropy Isn't That Hard

Kent Borg kentborg at borg.org
Fri Sep 13 12:18:02 EDT 2013

On 09/13/2013 11:59 AM, Marcus Leech wrote:
> Any physical-world sensor driver, where the sensor inherently has a 
> bit of noise, I think has a "moral obligation" to contribute bits to 
> the kernel entopy pool.

Within limits.  Mixing the entropy pool on Linux takes work and battery 

Looking at some random Android kernel source code (git commit c73c9662) 
it looks like add_interrupt_randomness() is happening for every 
interrupt (your Android device's kernel may vary), so there is probably 
plenty of entropy.  And add_interrupt_randomness() throttles to only 
feed the randomness once a second, not wasting our time or battery.

Don't carry moral obligation beyond what is reasonable!


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