Shamira Changeset - 8cbbc92dd17c

Changeset - 8cbbc92dd17c

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Laman - 4 years ago 2020-12-18 12:00:38

updated measurements for a new machine

2 files changed with 31 insertions and 4 deletions:

performance.md

readme.md

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performance.md

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@@ new file 100644 @@
 # Performance comparison #
 ## The base case ##
 Let's assume we have a secret of length _m_. The splitting takes _n_ evaluations of a polynomial of order _k_ (over Galois field 256) for each byte, leading to _O(n\*k\*m)_ finite field multiplications. Reconstruction of the constant parameters during joining first precomputes parts of the Lagrange polynomial and then reuses them for each byte, taking _O(k\*k + k\*m)_ multiplications.
 Benchmark results. The times for split and join mean _seconds per byte_ of the secret length:
 <table>
     <tr>
         <th>Revision</th>
         <th>Features</th>
         <th>k / n parameters</th>
         <th>Split</th>
         <th>Join</th>
     </tr>
     <tr>
         <td rowspan="2">a47ae3e113cc</td>
         <td rowspan="2">-</td>
         <td>2 / 3</td>
         <td>5.02e-06</td>
         <td>4.12e-05</td>
     </tr>
     <tr>
         <td>254 / 254</td>
         <td>0.0125</td>
         <td>0.00175</td>
     </tr>
 </table>
@@ \ No newline at end of file @@

readme.md

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@@ @@ -5,40 +5,40 @@ Implements [Shamir's secret sharing algo @@
 Outputs the shares as hexadecimal, Base32 or Base64 encoded strings.
 ## Installation and usage ##
 Can be run straight from the cloned repository by executing the package with `python -m shamira` or simply installed with `python setup.py build`, `python setup.py install`. Then imported in your code with `import shamira` or run from the command line with `shamira`.
 ## Performance ##
 As it is, the code is not very fast. Let's assume we have a secret of length _m_. For each byte, the splitting takes _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.
 Benchmark results, 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>
     </tr>
     <tr>
         <td>2 / 3 (a laptop)</td>
         <td>8.7e-06</td>
         <td>7.17e-05</td>
         <td>5.02e-06</td>
         <td>4.12e-05</td>
     </tr>
     <tr>
         <td>254 / 254 (a Raspberry Pi 3)</td>
         <td>0.226</td>
         <td>0.0314</td>
     </tr>
     <tr>
         <td>254 / 254 (a laptop)</td>
         <td>0.0209</td>
         <td>0.00347</td>
         <td>0.0125</td>
         <td>0.00175</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`

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