Pairwise security of the actual first affine phase #
The three actual calls give a pairwise guarantee from the original normalized source factors, a uniform honest right input, unequal advice, and finite numerical budgets. Both laws retain the complete executed transcript and original right state. The left-contribution guarantee is suited to subsequent merging; the masked-output guarantee concerns the actual program. Neither theorem assumes an intermediate seed certificate.
This proves the pairwise first phase of the standard-to-affine conversion in Chattopadhyay--Liao, Extractors for Sum of Two Sources (2021), Theorem 6.1, printed p.23, for the displayed actual components and budgets: https://arxiv.org/abs/2110.12652. The later subset-doubling rounds are required to obtain joint security against all tamperings.
Original source assumptions bound the actual left contributions against one tampering.
The complete actual masked first phase satisfies the pairwise strong guarantee.