# FAQs

Frequently asked questions.


## How does NiceTou.ch protect my inbox?

NiceTou.ch uses a few different ways to protect you from spam.

### 1. Active Hashcash

[Active Hashcash](https://github.com/BaseSecrete/active_hashcash) is an open-source library we developed to protect Ruby on Rails applications. NiceTou.ch now makes it available to all websites independently of the technology they use.

Hashcash is a proof-of-work algorithm, invented by Adam Back in 1997, to protect systems against denial-of-service attacks.  ActiveHashcash is an easy way to protect any Rails application from brute-force attacks and bots.

The idea is to force clients to spend time solving a hard problem that the server can easily verify. We developed ActiveHashcash after seeing brute-force attacks against our Rails application monitoring service, [RoRvsWild](https://www.rorvswild.com).

ActiveHashcash is ideal for sensitive forms such as login and registration. While the user fills out the form, JavaScript solves the problem and sets the result in a hidden text input. The form cannot be submitted until the proof of work is found. Then the user submits the form, and the controller verifies the stamp in a before action.

It blocks bots that do not interpret JavaScript because they cannot compute the proof of work. It also slows more sophisticated bots and brute-force attacks.  Moreover, the complexity increases automatically for IP addresses sending many requests. This makes it very CPU-intensive for attackers.

### 2. AI spam detection

Once Hashcash is solved, a local AI model assigns the message a spam score.
If the score is too high, we flag the message as spam and don't deliver it to your inbox. You'll still be able to see it in your NiceTou.ch account.

This greatly limits spam messages sent by smarter bots that manage to get through other protections, or by real human spammers trying to sell you something.

### 3. Sender email verification

If the message is not flagged as spam, we verify the sender's email address. We send them an email with a link they must click to proceed.

This prevents you from receiving emails from people you can’t respond to because they entered a typo or a fake address. This also reduces the risk of impersonation and bad jokes.

### 4. Email address hiding

If a message goes through all previous filters, it lands in your mailbox. 
It is only when you reply that your email address is revealed to the message sender. Then you can communicate directly. 

## What if a spam message reaches my inbox, or a legitimate message is marked as spam?

Securing your inbox is an ongoing battle. You can contact us to report any issues so we can improve protections.

## Questions? 

[Contact us](/en).