A new Protocol for 1-2 Oblivious Transfer

A new protocol for 1-2 (String) Oblivious Transfer is proposed. The protocol uses 5 rounds of message exchange.

💡 Research Summary

The paper introduces a novel 1‑2 string Oblivious Transfer (OT) protocol that operates in exactly five communication rounds. The participants, Alice (sender) and Bob (receiver), first agree on public parameters: a security parameter (n), a prime modulus (p) of size roughly (2\sqrt{n}\log n), an (n\times n) matrix (C) over (\mathbb{F}_p), a cryptographic hash function (h_1) mapping field elements to (q)-bit strings, and a one‑way function (h_2) mapping (q)-bit strings to (q’)-bit strings.

Round 1 (Alice → Bob). Alice samples random bits (t_1,\dots,t_n), two distinct field elements (a\neq b), two independent generators (\alpha_a,\alpha_b) of the multiplicative group (\mathbb{F}_p^\times), and two random permutations (\sigma_a,\sigma_b) of ({1,\dots,n}). For each column (j) she computes
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