Function peak_cycle_bytes 

pub fn peak_cycle_bytes<S: PixSpec>(params: &PixParams) -> u64

Worst-case live heap one Exit-side SSA cycle can hold, in bytes.

This is the figure the Session layer’s live-cycle budget is denominated in, and it is deliberately the adversarial peak rather than the conforming one. Nothing constrains the order in which an Entry emits shares within a cycle: the shipped generator walks polynomials in blocks of SHARE_EMISSION_WINDOW, so only that window holds share buffers at once and a conforming cycle peaks five times below this — 7.8 MiB against 39.1 MiB measured at the deployed dimensions — but a peer running anything else can drive every polynomial to one share short of its threshold and hold the lot. SsaPartBuilder::release_verification_state frees a buffer when its polynomial reconstructs; a polynomial one share short never reconstructs.

Not free to the peer, which is why this is a capacity bound and not a security one: a share only reaches the Exit on a return SURB the Exit itself spends, so reaching this peak costs a full quota deposit per cycle. What it bounds is an Exit selling more service than its memory can hold.

Excludes the awaiting-acknowledgement buffer, which is bounded separately and globally by max_ack_buffer_bytes — counting it here would charge the same bytes twice.