In the disclosed transaction processing system, a system and method are described that increase the ease of access and use of different currency networks by consumers using customizable transaction devices. The customizable transaction devices may be re-programmed prior to or during a currency transaction in accordance with the consensus protocol of the currency network associated with the currency transaction. The currency network further includes one or more host devices, each of which include an interface configured to communicate with a transaction device for the purposes of re-programming a Field Programmable Gate Array (FPGA) of the transaction device according to one or more currency network consensus protocols. Optimizing the performance of transaction devices for proof-of-work or other consensus protocol processing decreases the latency associated with validating currency network transactions, thereby increasing the suitability of cryptocurrency for retail transactions.