Security

import { integer, shuffle, token } from "ransu/secure";

ransu/secure mirrors the root API on top of the platform CSPRNG and refuses to be seeded. Reach for it whenever an attacker gaining an advantage would matter.

Which to use

Situation	Import from
Session tokens, API keys, password resets	ransu/secure or token()
Invite and coupon codes	ransu/secure
Prize draws, lotteries, matchmaking	ransu/secure
A shuffle a player must not predict	ransu/secure
Games, simulations, UI, test data	ransu

Identifiers are already secure

uuid, nanoid, ulid, token, otp and password draw from the CSPRNG even when imported from the root. You only lose that by passing an engine on purpose, which exists for tests.

Why not just seed something

A seeded generator is reproducible, and reproducible means predictable. Anyone who learns the seed can compute every value you will ever draw from it. That is why ransu/secure has no seed:

import { seed } from "ransu/secure";
seed();
// RansuError: ransu/secure cannot be seeded — a predictable stream would
// defeat its purpose.

What ransu does not do

• It does not implement encryption, signing or key derivation.
• The ChaCha20 engine exists to give a seeded stream that is hard to predict — a prize draw you can replay for an auditor. It is not exported as a cryptographic primitive.
• Timing side channels are out of scope, though the rejection loops in ransu/secure do not branch on secret values.