Maurice Hason

<p>Limesnip Simple2FA adds email-based two-factor authentication to your site. After entering their username and password, users receive a 6-digit verification code via email that they must enter to complete login.</p>
<p><strong>Features:</strong></p>
<ul>
<li>Email-based 2FA – no authenticator app required</li>
<li>Clean, Linear-inspired verification UI</li>
<li>Auto-advancing digit inputs with paste support</li>
<li>Auto-submit when all digits are entered</li>
<li>Role-based enforcement – choose which roles require 2FA</li>
<li>Configurable code expiration and max attempts</li>
<li>Optional “Remember this device” feature</li>
<li>HTML and plain text email support</li>
<li>Secure code storage (SHA-256 hashed)</li>
<li>Fully responsive design</li>
</ul>


Limesnip Simple2FA

Simple email-based two-factor authentication for WordPress. Adds a clean, Linear-inspired verification screen to your login flow.

rishav001

<p>Rishav AuthNova OTP adds a one-time-password verification layer to core WordPress authentication flows.</p>
<p>Features include:</p>
<ul>
<li>Configurable OTP length and charset (numeric or alphanumeric)</li>
<li>OTP expiry and retry limits with temporary lockouts</li>
<li>Login OTP verification step (after password check)</li>
<li>OTP-gated registration flow</li>
<li>OTP-gated password reset flow</li>
<li>Delivery via wp_mail, SendGrid, and Twilio</li>
<li>OTP storage using hashes (never plaintext)</li>
<li>Resend OTP with cooldown and challenge rotation</li>
</ul>
<p>Security highlights:</p>
<ul>
<li>OTP values are hashed before storage and are never saved as plaintext</li>
<li>OTP hashes use keyed HMAC storage and constant-time verification</li>
<li>OTP challenges expire automatically and enforce retry limits per challenge</li>
<li>Request throttling applies cooldown and exponential backoff per IP and identifier</li>
<li>Lockout windows reduce repeated invalid OTP submissions</li>
<li>Nonces are applied on sensitive form submissions</li>
<li>Public auth responses are intentionally generic to reduce account-enumeration leakage</li>
<li>Delivery uses synchronous-first send with bounded async retry fallback and challenge-level delivery status tracking</li>
</ul>
<p>Security limitations:</p>
<ul>
<li>This plugin does not replace passwords, HTTPS, WAF/rate-limiting at the edge, or secure hosting controls</li>
<li>OTP delivery depends on the configured email/SMS provider uptime and deliverability</li>
<li>Administrators should combine this plugin with standard WordPress hardening and monitoring</li>
</ul>
<p>Reliability notes:</p>
<ul>
<li>OTP delivery is attempted synchronously first to reduce silent failures</li>
<li>If synchronous delivery fails and background delivery is healthy, the plugin schedules bounded retries</li>
<li>If background delivery is unhealthy (for example DISABLE_WP_CRON), fallback queueing is skipped and users receive a retry-safe error</li>
<li>Resend cooldown state is server-authoritative and exposed through a status endpoint used by frontend countdown UX</li>
<li>Background queue payload contains only challenge ID (no raw OTP or destination data)</li>
</ul>
<h3>External Services</h3>
<p>This plugin can connect to third-party services to deliver OTP messages. These services are optional and only used if enabled in plugin settings.</p>
<h4>Twilio (SMS Delivery)</h4>
<ul>
<li>Service: Twilio Programmable Messaging API</li>
<li>Purpose: Send OTP codes by SMS</li>
<li>Data sent: destination phone number, sender phone number, OTP message text, account SID for authentication</li>
<li>Credential handling: Twilio credentials are stored in WordPress options and used only when sending OTP messages</li>
<li>When sent: when OTP delivery method includes SMS and an OTP is generated for login, registration, password reset, or resend</li>
<li>Why sent: to deliver time-sensitive OTP codes to the user by SMS</li>
<li>Terms of Service: https://www.twilio.com/legal/tos</li>
<li>Privacy Policy: https://www.twilio.com/en-us/legal/privacy</li>
</ul>
<h4>SendGrid (Email Delivery)</h4>
<ul>
<li>Service: SendGrid Mail Send API</li>
<li>Purpose: Send OTP codes by email</li>
<li>Data sent: recipient email address, sender email/name, message subject, OTP message body, API key for authentication</li>
<li>Credential handling: SendGrid API key is stored in WordPress options and used only when sending OTP messages</li>
<li>When sent: when email provider is set to SendGrid and an OTP is generated for login, registration, password reset, or resend</li>
<li>Why sent: to deliver time-sensitive OTP codes to the user by email</li>
<li>Terms of Service: https://sendgrid.com/policies/terms/</li>
<li>Privacy Policy: https://sendgrid.com/policies/privacy/</li>
</ul>
<h3>Configuration</h3>
<ol>
<li>Set OTP length, type, expiry, retry limit, and lockout duration.</li>
<li>Choose delivery method: Email, SMS, or Both.</li>
<li>Configure provider credentials for SendGrid and/or Twilio if needed.</li>
<li>Enable or disable OTP on login, registration, and password reset flows.</li>
</ol>


Rishav AuthNova OTP

OTP verification for WordPress login, registration, and password reset using email and SMS delivery.

Limesnip Simple2FA vs Rishav AuthNova OTP