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Microsoft SEAL is the only fully homomorphic library available among a sea of partially homomorphic libraries in the JavaScript domain. SEAL can operate on all batched elements in parallel with no cost as Single Instruction, Multiple DataSIMD (SIMD) or Multiple Instruction, Single Instruction (SIXIX) SEAL can also operate on the number of data you are allowed to encode using the BatchEncoder. For very simple applications Paillier may be a better choice for simple applications, SEAL for complex applications.