Current computer systems use encryption extensively, for example,in instant messaging, virtual private network protocols, andwebsites in general. However, employing encryption in a systemcan be computationally costly, resulting in lower throughput orhigher latencies. One strategy to mitigate the costs imposed by theapplication of cryptography is the use of accelerators dedicatedto the execution of this task. In this context, this paper presentsthe development of an encryption accelerator for the ChaCha20stream cipher. The accelerator was prototyped on two FPGA SoCplatforms, achieving a normalized speedup of 3.49 times comparedto the software implementation.