README.md in fernet-0.0.1 vs README.md in fernet-0.0.2

@@ -22,13 +22,37 @@
 
     $ gem install fernet
 
 ## Usage
 
-For now, see [spec/fernet_spec.rb](https://github.com/hgimenez/fernet/blob/master/spec/fernet_spec.rb).
+Both server and client must share a secret.
 
-I'll flesh this out further soon. Sorry.
+You want to encode some data in the token as well, for example, an email address can be used to verify it on the other end.
 
+```ruby
+token = Fernet.generate(secret) do |generator|
+  generator.data = { email: '[e-mail]' }
+end
+```
+
+On the server side, the receiver can use this token to verify wether it's legit:
+
+```ruby
+verified = Fernet.verify(secret, token) do |verifier|
+  verifier.data['email'] == '[e-mail]'
+end
+```
+
+The `verified` variable will be true if:
+
+* The email encoded in the token data is `[e-mail]`
+* The token was generated in the last 60 seconds
+* The secret used to generate the token matches
+
+Otherwise, `verified` will be false, and you should deny the request with an HTTP 401, for example.
+
+The specs ([spec/fernet_spec.rb](https://github.com/hgimenez/fernet/blob/master/spec/fernet_spec.rb)) have more usage examples.
+
 ## License
 
-Valcro is copyright (c) Harold Giménez and is released under the terms of the
+Fernet is copyright (c) Harold Giménez and is released under the terms of the
 MIT License found in the LICENSE file.