[Cryptography] Entropy is forever ...

[Thierry Moreau]

On 04/21/15 20:36, John Denker wrote:
> On 04/21/2015 07:10 AM, Thierry Moreau wrote:
>
>> Take a 256 bits PRNG seed and a 256+8=264 bits random message source
>> with with a uniform distribution for the 2^264 messages except that a
>> specific message occurs 16 times more often. The minimum entropy
>> measure would thus be 260 (based on the message sample with the
>> highest probability).
>
> The quantity calculated there is called the /surprisal/.
> It is not properly called the entropy, or the min-entropy,
> or anything like that.
>

http://en.wikipedia.org/wiki/Min_entropy

This concept is used in NIST documents for a conservative estimate of 
randomness from a hardware random source.

Regards,

- Thierry