> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mainwp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Custom signature algorithm and PHPSecLib as alternative to OpenSSL

> Configure custom signature algorithms and use PHPSecLib as an alternative to OpenSSL for Dashboard-to-Child communication.

MainWP Dashboard version 4.5 introduced the ability to set a custom signature algorithm and added PHPSecLib as an alternative to OpenSSL. Both options can be configured globally or on a per-site basis.

## What You'll Learn

* When to change the signature algorithm
* How to switch between OpenSSL and PHPSecLib
* How to configure these settings per site

## Prerequisites

* MainWP Dashboard version 4.5 or later
* Admin access to your Dashboard

***

## Signature Algorithm

### Background

MainWP uses digital signatures to verify communication between Dashboard and Child Sites. Previously, MainWP used SHA1 for signature verification. As hosts updated to OpenSSL 3, some disabled SHA1 as a legacy option.

MainWP now defaults to SHA256, which provides enhanced security and works with both OpenSSL 1 and OpenSSL 3.

### Change the Global Signature Algorithm

If your Dashboard host doesn't support a certain SHA algorithm, connections may fail.

<Steps>
  <Step title="Open Advanced Settings">
    Go to **MainWP Dashboard > Settings > Advanced Settings**.
  </Step>

  <Step title="Select algorithm">
    Find **OpenSSL signature algorithm** and select a supported algorithm.

    <img src="https://mintcdn.com/mainwp/OKpZbeo5_cAajLyl/images/miscellaneous/advanced-custom-signature-algorithm-and-phpseclib-as-alternative-to-openssl.mdx-0168b4.gif?s=bded6980319aed33d7ebbc33669a5ade" alt="Animation showing OpenSSL signature algorithm selection in Advanced Settings" width="751" height="568" data-path="images/miscellaneous/advanced-custom-signature-algorithm-and-phpseclib-as-alternative-to-openssl.mdx-0168b4.gif" />
  </Step>

  <Step title="Save settings">
    Save your changes.
  </Step>
</Steps>

Most hosts support SHA256. If yours doesn't, contact support to ask which algorithms they support.

<Note>
  Signature verification happens after a site is added to the Dashboard. If verification fails, the site can still be added, but sync and other authenticated actions will fail.
</Note>

### Switching Back to SHA1

To switch from SHA256 to SHA1 (globally or for specific sites), you must reconnect affected child sites:

1. Visit each child site's WP Admin
2. Deactivate and reactivate the MainWP Child plugin (this disconnects it)
3. Reconnect the site from your Dashboard

***

## PHPSecLib as Alternative to OpenSSL

### When to Use PHPSecLib

PHPSecLib is a pure PHP implementation of cryptographic functions. Use it when:

| Scenario             | Description                                        |
| -------------------- | -------------------------------------------------- |
| OpenSSL unavailable  | Server doesn't have OpenSSL installed              |
| Configuration issues | OpenSSL misconfigured (common on localhost setups) |
| openssl.cnf problems | Cannot locate or configure the openssl.cnf file    |

If OpenSSL works properly on your host (most web hosts), there's no need to switch to PHPSecLib.

### Enable PHPSecLib Globally

<Steps>
  <Step title="Open Advanced Settings">
    Go to **MainWP Dashboard > Settings > Advanced Settings**.
  </Step>

  <Step title="Change connection method">
    Find **Verify connection method** and select **PHPSecLib**.

    <img src="https://mintcdn.com/mainwp/OKpZbeo5_cAajLyl/images/miscellaneous/advanced-custom-signature-algorithm-and-phpseclib-as-alternative-to-openssl.mdx-7da51c.gif?s=ea62ea67ceb12023b2be8366434faff2" alt="Animation showing PHPSecLib selection in Verify connection method setting" width="686" height="576" data-path="images/miscellaneous/advanced-custom-signature-algorithm-and-phpseclib-as-alternative-to-openssl.mdx-7da51c.gif" />
  </Step>

  <Step title="Save settings">
    Save your changes.
  </Step>
</Steps>

<Warning>
  Changing to PHPSecLib globally requires re-adding existing child sites. To avoid this, configure the setting per site instead.
</Warning>

***

## Per-Site Settings

Both signature algorithm and connection method can be configured per site. This is useful when a specific child site's host has different requirements.

<Steps>
  <Step title="Open site edit page">
    Go to **MainWP Dashboard > Sites > Manage Sites**.
  </Step>

  <Step title="Select the site">
    Click on the child site, then click **Edit**.
  </Step>

  <Step title="Find Advanced Settings">
    Scroll to the **Advanced Settings (Optional)** section.
  </Step>

  <Step title="Configure options">
    Set the signature algorithm and/or verify connection method for this specific site.

    <img src="https://mintcdn.com/mainwp/OKpZbeo5_cAajLyl/images/miscellaneous/advanced-custom-signature-algorithm-and-phpseclib-as-alternative-to-openssl.mdx-dd5fa6.gif?s=6eb634d94c3ec6a61000489948cd8d91" alt="Animation showing per-site signature and connection settings in Child Site Edit page" width="1068" height="899" data-path="images/miscellaneous/advanced-custom-signature-algorithm-and-phpseclib-as-alternative-to-openssl.mdx-dd5fa6.gif" />
  </Step>

  <Step title="Save changes">
    Save the site settings.
  </Step>
</Steps>

***

## Self-Check Checklist

* [ ] Identified whether connection issues are signature or OpenSSL related
* [ ] Selected appropriate signature algorithm for your host
* [ ] Configured PHPSecLib if OpenSSL is unavailable
* [ ] Child sites connecting and syncing successfully

***

## Related Resources

* [OpenSSL Key Encryption](/advanced/openssl-keys-encryption) - Private key encryption
* [Find openssl.cnf](/advanced/how-to-find-the-openssl-cnf-file) - Locate OpenSSL configuration
* [MainWP Security](/getting-started/how-secure-is-the-mainwp-plugin) - Security overview