Embodiments of the invention are directed to methods, apparatuses, and systems for processing transactions using a master applet on a mobile device. One embodiment of the invention is directed to a method comprising a master applet associated with a mobile application of a mobile device determining available applications on a mobile device, displaying the available applications to a user, and receiving a selection of one of the available applications from the user. The method further comprises obtaining encrypted credentials from the selected application, generating an encrypted payload including the encrypted credentials and transaction data using a master applet encryption key associated with the applet, and sending the encrypted payload to a processor computer. The processor computer decrypts the encrypted payload using a master applet decryption key, decrypts the encrypted credentials using a selected application decryption key, and uses the decrypted credentials and transaction data to initiate a transaction.