@@ -27,38 +27,36 @@ Run `shamira split ...` for splitting an
## Issue tracker
Please report your issues to https://trac.19x19.cz/shamira/report
## Performance ##
Asitis, the code is not very fast. Let'sassumewehaveasecretoflength_m_.Foreachbyte, the splittingtakes _n_ evaluations of a polynomial of order _k_ over Galois field 256, leading to _O(n\*k\*m)_ finite field multiplications. Reconstruction of the constant parameters during joining takes _O(k\*k + k\*m)_ multiplications.
Being written in pure Python, the code is not especially fast. It is therefore recommended to split rather keys to encrypted files than the files themselves.
Benchmark results, all values mean _seconds per byte_ of the secret length:
Benchmark results, as obtained by running `shamira benchmark`. All values mean _seconds per byte_ of the secret length:
<table>
<tr>
<th>k / n parameters</th>
<th>Split</th>
<th>Join</th>
</tr>
<tr>
<td>2 / 3 (a Raspberry Pi 3)</td>
<td>6.08e-05</td>
<td>0.000435</td>
<td>0.000142</td>
<td>0.000448</td>
</tr>
<tr>
<td>2 / 3 (a laptop)</td>
<td>5.02e-06</td>
<td>4.12e-05</td>
<td>7.88e-06</td>
<td>4.28e-05</td>
</tr>
<tr>
<td>254 / 254 (a Raspberry Pi 3)</td>
<td>0.226</td>
<td>0.0314</td>
<td>0.0268</td>
<td>0.0287</td>
</tr>
<tr>
<td>254 / 254 (a laptop)</td>
<td>0.0125</td>
<td>0.00175</td>
<td>0.00183</td>
<td>0.00156</td>
</tr>
</table>
While the speeds are not awful, for longer secrets I recommend encrypting them with a random key of your choice and splitting only the key. Anyway, you can run your own benchmark with `shamira benchmark`