1970-01-01

(2026-04) A Simple Batched Threshold Encryption Scheme

• [[Guru-Vamsi Policharla]]

2026-04-17

Abstract

In this note, we construct a simple batched threshold encryption scheme that satisfies censorship resistance, does not suffer from epoch restrictions, and has quasi-linear decryption complexity $O(B\log{B})$ in the batch size $B$. Our scheme has a CPA secure ciphertext size of $|\mathbb{G}_1| + |\mathbb{G}_T|$, and a CCA secure ciphertext size of $|\mathbb{G}_1| + 2|\mathbb{F}| + |\mathbb{G}_T|$. Our construction requires an interactive setup phase (involving secure multiplications) and has secret keys that grow linearly with the batch size.