Public-key cryptosystems such as elliptic curve cryptography (ECC) and Rivest–Shamir–Adleman (RSA) are widely used for data security in computing systems. ECC provides a high level of security with a much smaller key than RSA, which makes ECC a preferred choice in many applications. This study proposes a multi-key ECC based on the residue number system. The proposed architecture employees deep pipelining to allow the concurrent encryption of 21 keys. The proposed architectures are implemented on two different field programmable gate array (FPGA) platforms and results are compared with existing ECC architectures. The proposed implementation on Virtex-7 FPGA achieves a throughput of 1816 kbps at a clock frequency of 73 MHz.