How can mod_rewrite be utilized to pass data securely in PHP applications?

When passing data securely in PHP applications using mod_rewrite, one approach is to use URL rewriting to hide sensitive data in the URL. This can be achieved by rewriting the URL to include encrypted data that can be decrypted on the server side to retrieve the original data. By using mod_rewrite to pass data securely, sensitive information such as user IDs or tokens can be protected from being exposed in the URL.

```php
RewriteEngine On
RewriteRule ^user/([a-zA-Z0-9]+)$ user.php?id=$1 [L]
```

In this example, the mod_rewrite rule rewrites the URL from `user.php?id=123` to `user/123`, where `123` is the user ID. This way, the user ID is not exposed in the URL, providing a more secure method of passing data in PHP applications.