Abstract: A cryptographic expansion device that can be attached to a communication component of a communication device to enable the communication device to perform cryptographic operations on communications sent to and from the communication device is described. The cryptographic expansion device can be a small-form factor cryptographic expansion device that can be used with a small-form factor communication component such as a micro-SIM (subscriber identity module) card. When used with a communication device, the cryptographic expansion device enables the communication device to send and received end-to-end secure encrypted communications. The end-to-end secure communications enabled by the cryptographic expansion device can be utilized by a user of the communication device to perform financial and/or banking transactions.