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<li>Change the number of traces to be ''1000'': more traces are needed to form the profile. In this case 1000 is a very small capture, however for this unprotected implementation will be sufficient. An interesting experiment is to see how using more or less traces impacts your templates!</li>
<li>Hit the ''Capture Many'' button (M in a green triangle) to start the capture process. You will see each new trace plotted in the waveform display. Once the capture is complete, save the project file again.</li>
=== Capturing the Attack Traces ===
# Follow steps 1Make a new project (File-3 of the previous section>New). Leave the ''Key/Text Pattern'' as default, where # Change the encryption key is to fixed and the plaintext is random.
# Save the project now in the same directory as the <code>.cwp</code> file from the previous section, giving it a name indicating the key is '''fixed''' and text is '''random'''. For example you could call it <code>tut_fixedkey_randplain.cwp</code>, again saving it in the same directory as the previous file.
# Change the number of traces to be ''20'': by comparison the profiling attack will require less attack traces compared to the CPA attack.
# Hit the ''Capture Many'' button (M in a green triangle) to start the capture process. You will see each new trace plotted in the waveform display. Once the capture is complete, save the project file again.
# Exit the capture application, again being sure to first save the project.
== Generating the Template ==
<li>Open the Analyzer software</li>
<li>From the ''File --> Open Project'' option, navigate to the <code>tut_randkey_randplain.cwp</code> file you save previously. Open this file, ensure it is the file corresponding with the '''randomly changing encryption key'''!</li>
<li>Open the ''Trace Explorer'' by selecting tab and Enable it from the ''Tools'' menu.</li><li><p>Change the "Comparison Mode" to "Sum of Absolute Difference", the ''Partition Mode'' to ''HW AES Intermediate'', and select the ''Auto-Save Data to Project'' option:</p>
<p>[[File:traceexplorer1.png|image]]</p></li>
<li><p>Hit the ''Display'' button, and then select ''All On''. This displays the differences between the various groups of Hamming Weight (HW) values:</p>
</blockquote>
<ol start="7" style="list-style-type: decimal;">
<li>Close Disable the Trace Explorer window.</li>
<li><p>Change the attack module to ''Profiling'':</p>
<p>[[File:selectprofiling.png|image]]</p></li>
<li><p>Go to the ''Template Generation'' sectionin the Attack tab, and ensure you select the appropriate trace range (0-999 in this example). Select the ''TraceExplorer Table'' as the POI source, since we had just populated this with a valid POI data. Notice that if you view the analysis script it will list the poi you selected, if not hit the ''Read POI'' button:</p>
<p>[[File:templategeneration.png|image]]</p></li>
<li>Click the ''Generate Templates'' button. This will dynamically load and run the <code>def generateTemplates(self):</code> function in the scripting window.</li>
partitiontype = PartitionHWIntermediate
filename = avr_keyrand_plainrand_1000traces_data\analysis\templates-PartitionHWIntermediate-0-999.npz</pre></li>
== Applying the Template ==
<ol style="list-style-type: decimal;">
<li>From the ''File --> Open Project'' option, navigate to the <code>tut_fixedkey_randplain.cwp</code> file you save previously. Open this file, ensure it is the file corresponding with the '''fixed encryption key'''!</li>
<li>Open the project text editor if not already open.</li>
<li><p>Append the ''Template Data'' section you copied from the previous project to your project file:</p>
<p>[[File:projecteditor_addtemplate.png|image]]</p></li>
<li>Use the ''Save Editor to Disk'' button to write these changes(and '''not the Save Project option'''). Note this assumes that both the <code>tut_fixedkey_randplain.cwp</code> and <code>tut_randkey_randplain.cwp</code> were saved in the same directory, as otherwise the reference to the template file will break!</li><li>Close the Analyzer software. Re-open the software and reload the same project file (e.g. <code>tut_fixedkey_randplain.cwp</code>), this step is needed to ensure the changes you added in are loaded into memory.</li>
<li><p>Change the attack module to ''Profiling'':</p>
<p>[[File:selectprofiling.png|image]]</p></li>
<li><p>Press the ''Attack'' button. Observe that with only a few traces you are able to determine the encryption key:</p>
<p>[[File:attack_working.png|image]]</p></li></ol>
== Links ==
{{Template:Tutorials}}
[[Category:Tutorials]]
