A field-programmable gate array (FPGA) cluster, comprising a plurality of FPGA devices, can be used to accelerate homomorphic encryption functionality. In particular, the FPGA cluster can accelerate the relinearization process used in homomorphic encryption by using multiple FPGA devices to perform portions of the relinearization process in parallel. Further, the use of the FPGA cluster provides sufficient memory resources to allow data used by the relinearization process, namely the keyswitch keys, to be stored on-chip.