Difference between revisions of "Distribution of nonces and hashes"

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(added nonce, hash, and 2-D nonce vs. hash histograms)
m (Histograms: added Wikipedia:Selection bias link)
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==Histograms==
 
==Histograms==
The nonces found are skewed toward 0 because this is a selection effect: most everyone starts searching for nonces starting at 0:<br>[[File:Nonces Histogram.png|histogram of nonces]]
+
The nonces found are skewed toward 0 because this is a [[Wikipedia:Selection_bias|selection effect]]: most everyone starts searching for nonces starting at 0:<br>[[File:Nonces Histogram.png|histogram of nonces]]
  
 
Although the distribution of hashes is not uniform, this does not matter; all that matters is that the distribution of nonces is uniform (which they are, minus the selection effect of starting at 0):<br>[[File:Hashes Histogram.png|histogram of hashes]]
 
Although the distribution of hashes is not uniform, this does not matter; all that matters is that the distribution of nonces is uniform (which they are, minus the selection effect of starting at 0):<br>[[File:Hashes Histogram.png|histogram of hashes]]

Revision as of 01:00, 14 March 2015

Here we analyze the nonce values and hashes for all the valid blocks in the blockchain:[1]

Time Evolution

Nonces vs Hashes (y-axis logarithmic, x-axis linear)

This plot readily shows that the distribution of nonces that produce valid hashes is uniform.
verba alia

Nonces vs Hashes (log-log scale)

Nonces vs Hashes (log-log scale)

In the animated version of this last plot,[2] you can really visualize the change in the difficulty and even see where the difficulty was decreased.

Histograms

The nonces found are skewed toward 0 because this is a selection effect: most everyone starts searching for nonces starting at 0:
histogram of nonces

Although the distribution of hashes is not uniform, this does not matter; all that matters is that the distribution of nonces is uniform (which they are, minus the selection effect of starting at 0):
histogram of hashes

2-D histogram of hashes and nonces (logarithmic color scale):
Density Plot (log colorscale)
This also illustrates very well that the distribution of nonces is uniform.

References

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