stdlib-point-at-infinity

What problem does it solve?

Prevents incorrect handling of point-at-infinity representations in stdlib circuit types, avoiding broken serialization, hashing, public inputs, and recursive verification when infinity may appear with non-canonical coordinates.

Core Features & Use Cases

• Canonically normalize infinity at circuit boundaries: Ensures grumpkin_commitment infinity is converted to the (0,0) convention via conditional_assign where it can be produced non-canonically.
• Differentiate representation models across element types: Guides correct usage for bn254 element_default (explicit infinity flag) vs goblin_element (infinity encoded as (0,0)).
• Handle recursion safely: Recommends conditional_assign instead of BB_ASSERT on values potentially influenced by a malicious prover during recursive verifier circuit construction.
• Use correct comparison/serialization touchpoints: Identifies observation boundaries (serialize_to_fields, set_public, operator==/assert_equal) where canonicalization must occur for correctness.

Quick Start

Use this guidance when implementing stdlib serialization/public-input wiring for cycle_group and bn254 commitment types so infinity is treated as (0,0) at boundaries and normalized with conditional_assign where needed.