lass="text-justify">Given the user's IP address, challenge <span class="math-term">C</span> and nonce <span class="math-term">i</span>, the server can look up the session of the user in its in-memory database,
                            from which it checks that the challenge still exists, the
                            timestamp <span class="math-term">T</span> is not older than the maximal submission time (<span th:text="${settings.maxSessionTime}"></span> seconds), and that
                         