Wireframes: Add user

This process allowed users to add trusted friends in a securely. The challenge was to simplify a complicated process. Unique design concepts:

• In order to provide as much security for our users as possible, we require both participants to be online for the entire process. This drastically decreases the chances of an attacker “mimicking” one of the participants.

• The two parties have to use an alternate form of communication i.e a phone call to exchange keys. This is a way to perform “user initiated two-factor authentication”.

• To simplify the process, we made each section very clear with only one command.

WIREFRAMES: Sending encrypted message

Since this is a highly repeated process, we needed it to be as smooth and unobtrusive as possible. The challenge was how to achieve this without compromising user safety. Unique design concepts:

• To keep message encryption time low, we used a variant of the Diffie-Hellman symmetric key exchange. This allowed us to encrypt large amounts of text in a safe manner quickly. It also allowed us to create disposable keys for each message. Adding yet another layer of security.

• To make sure that no message is ever stored on our servers or the devices, we require both users to be online when messages are being sent. This way when a message is received, it can be read and destroyed immediately.

For inspiration, we looked at how people in history kept their messages secret. We discovered that pirates, due to the nature of their profession, had to develop extremely safe yet easy to learn communication protocols. Tools such as the morse code and flag signal all derived in some form from the pirates.

We kept to the pirate theme and picked colours that we reflected the sea. Something vast and deep. We also looked at other colour schemes through Adobe "Kuler", but found this to be the most visually satisfying.

The app was launched to the app store in early 2015.