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@lelantos-org/sdk / crypto / Poseidon

Class: Poseidon ​

Defined in: @lelantos-org/sdk/dist/crypto/poseidon.d.ts:5

Properties ​

backend ​

ts
readonly backend: PoseidonBackend;

Defined in: @lelantos-org/sdk/dist/crypto/poseidon.d.ts:11

Which implementation arity-5 hashes use. "js" means the wasm module did not load and every hash is ~2.5x slower — worth asserting in benchmarks and worth checking first when a sync is unexpectedly slow.

hash ​

ts
readonly hash: (xs) => bigint;

Defined in: @lelantos-org/sdk/dist/crypto/poseidon.d.ts:34

Inputs must already be canonical field elements, i.e. in [0, r).

poseidon-lite reduces mod r internally, so x and x + r hash identically. Every domain-separated construction in the SDK routes through here — nullifiers, note commitments, rho, the key ladder, merkle nodes — so without this check two distinct decoded records or two distinct merkle leaves can be made to collide by construction. Both decoders that feed it (notes/codec.ts, keys/address.ts) read raw 32-byte slices and can produce unreduced values.

The wasm backend rejects unreduced input rather than reducing it, so the two agree — but the check stays here to keep the error identical whichever backend is live.

One comparison per input against a full permutation: not measurable.

A bound property rather than a prototype method, so the class stays structurally { backend, hash } and the arity table can be captured per instance — the backend is a property of the instance, not of the call, so it must not be branched on per hash.

Parameters ​

ParameterType
xsbigint[]

Returns ​

bigint

Methods ​

build() ​

ts
static build(): Promise<Poseidon>;

Defined in: @lelantos-org/sdk/dist/crypto/poseidon.d.ts:46

Initialises the wasm backend. Already async before it did anything, so no caller changes.

A failure here is not fatal: the JS tables cover every arity, so an environment that cannot load wasm degrades to the slower backend rather than to a broken wallet. It is logged rather than swallowed — silently losing 2.5x is the kind of regression nobody notices until a cold sync takes a minute.

Returns ​

Promise<Poseidon>