0xCrypt

Try out how the basic ciphers work and get some intuition

coursework specifications

• Comprise of good quality UI with at least two fragments separating all the components.
• Use the activity life cycle states through its various methods (such as onStart, onPause, onDestroy, etc.).
• Utilise at least one: device location/ Google Maps/ Media player/ Camera/ microphone/ any native android apps, service, sensor, or sensor API.
• Use persistence data storage (e.g. SQLite, ROOM/ Firebase/Firestore, etc.).
• Use MVC or similar (java-based frameworks such as MVP, MVVM, etc.) framework.

TODO

• Template activity for standard ciphers, must be adapted depending on which cipher is used at runtime

• Make input fields, etc. look nice

• Debug Ciphers (especially Vigenere)

• Update settings page

• Put strings from update password xml into strings.xml

• Add another fragment (bottom) that is used to display more detailed information (xor: binary code, ...)

• Should work? SpeechRecognizer is not properly closed

• Weird that the fragments change their id's, probably bc they are the same and get overriden on change or smth? -> Just use the same id for the same buttons etc.

• Error messages for wrong input in encryption

• Change binary mode to switch instead of button

• Debug XOR cipher

• Descriptions/how to use for all ciphers

• Maybe issues when restoring data with isBinary in XOR?

• (Add key/password generator)

• Email changing not working; Would be a lot of effort to do it properly

• Add switch button (output text and msg)

• (We could also add the option to save inputs and have a history -> Lot of work, for now only the last used snapshot)

• Make 2 colour schemes, one for decrypting and one for encrypting

Firebase Realtime Database

• We use the Firebase Authentification Service to provide user accounts
• The last snapshot of a user is stored on the firebase realtime database (a snapshot contains key, message and output of all ciphers)
• When the user logs in again, his/her snapshot gets restored and he/she can continue working where he/she left

How is MVC implemented?

• The encryption/decryption process is fully separated from the frontend
• The cipher fragments simply call encrypt/decrypt with the corresponding cipher and input
• Furthermore, there is a simple DataModel created, that allows to easily store snapshots that can be saved. A snapshot consists of all the users in/output which is stored in the Prefs File locally and online if the user logs out.

Case Study / Problem

• Help people learn/understand how cryptography works in an intuitive and easy way. Lots of ways to expand:
  • Add new ciphers
  • Add Product ciphers (combination of transposition and substitution ciphers)
  • Add functionality to create/save ciphers; relevant for prodcut ciphers aswell
  • Add feedbackShiftRegister
  • $\dots$