om CodeIgniter 1.x’s Encryption library</td>
</tr>
<tr class="row-odd"><td><strong>$legacy_mode</strong></td>
<td>MCRYPT_MODE_ECB</td>
<td>The Mcrypt mode that was used to generate the original encrypted data.
CodeIgniter 1.x’s default was MCRYPT_MODE_ECB, and it will assume that
to be the case unless overridden by this parameter.</td>
</tr>
<tr class="row-even"><td><strong>$key</strong></td>
<td>n/a</td>
<td>The encryption key. This it typically specified in your config file as
outlined above.</td>
</t