How Encrypt module actually works? I installed the Drupal Encrypt module and enabled it. However, I wonder how this module actually works. Does it encrypt all the submissions from the browser that the user/admin key in like 1) Login  2) Add/update node  3) Contact form/webform and decrypted again in the server before saving to the database ? Any tool to test this process? I'm looking a way to protect all the submissions or update over the internet which may be captured or exposed especially in the public area when using those free Wi-Fi. Please advise.
The Encrypt module:


  provides an application programming interface (API) for performing two-way data encryption. It allows modules to encrypt data such that it can be decrypted using the same key that was used to encrypt the data. This is useful for storing sensitive information.


Emphasis mine. That's its purpose, to provide an API that other modules can use to encrypt data before it's stored in the database (or elsewhere I guess). 

As an API module, it provides no functionality unless you make explicit use of it; either by installing one of the modules listed that uses it, or by writing a custom module that does so. The emphasis is on you (or the writer of a contrib module) to actually do something useful with this module:


  It is up to the module calling encrypt() to manage and store the encrypted data.


The important thing to understand is that it doesn't (and couldn't) protect users from having their data sniffed over a public network. For that you'll need to use HTTPS, no exceptions. All this module does is offer an encryption/decryption service for your server-side app.