Enum FederatedCompositionMethod 

pub enum FederatedCompositionMethod {
    Basic,
    AdvancedComposition,
    FederatedMomentsAccountant,
    RenyiDP,
    ZCDP,
}

Federated composition methods.

Every variant treats the caller-supplied per-round (epsilon, delta) as a black-box (ε, δ)-DP guarantee and composes it over round applications. Mechanism-specific accountants (moments / RDP) that need the noise multiplier σ and the sampling rate q cannot be reconstructed from (ε, δ) alone; for tight per-step RDP accounting use crate::privacy::accountant instead.

Variants

Basic

Basic (linear) composition: ε' = k·ε. Always a valid upper bound.

AdvancedComposition

Advanced composition (Dwork–Roth, Thm 3.20): ε' = √(2k·ln(1/δ'))·ε + k·ε·(e^ε − 1), returned as min(ε', k·ε). The caller’s delta plays the role of the advanced-composition slack δ'; the composed mechanism’s total failure probability is k·δ_round + δ'.

FederatedMomentsAccountant

Moments-accountant-style composition.

A true moments accountant needs σ and q, which (ε, δ) does not carry, so this returns the conservative advanced-composition bound (an upper bound, never an under-estimate). Use crate::privacy::accountant for tight RDP.

RenyiDP

Rényi-DP-style composition.

Like Self::FederatedMomentsAccountant, RDP needs σ/q; this returns the conservative advanced-composition bound. Use crate::privacy::accountant.

ZCDP

Zero-concentrated DP composition.

Interprets the per-round (ε, δ) as a ρ-zCDP guarantee (the largest ρ consistent with ε = ρ + 2√(ρ·ln(1/δ))), composes ρ_total = k·ρ, and converts back. Only valid when the per-round mechanism really is ρ-zCDP (e.g. Gaussian); otherwise prefer Self::AdvancedComposition.

Trait Implementations

impl Clone for FederatedCompositionMethod

fn clone(&self) -> FederatedCompositionMethod

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for FederatedCompositionMethod

impl Debug for FederatedCompositionMethod

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for FederatedCompositionMethod

fn default() -> FederatedCompositionMethod

Returns the “default value” for a type.

impl Eq for FederatedCompositionMethod

impl PartialEq for FederatedCompositionMethod

fn eq(&self, other: &FederatedCompositionMethod) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for FederatedCompositionMethod