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Grafting: Improving Performance and Usability of Homomorphic Encryption
TL;DR: Grafting is a new approach for managing a CKKS ciphertext modulus. With so-called sprouts, we dedicate a few machine words to scaling and use word-sized primes for the remaining ciphertext modulus improving performance. With universal sprouts, we can represent any bit size up to the word size using powers-of-two and introduce arbitrary scaling for RNS-CKKS easing parameter and circuit design.