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Security · medium

31. Web Crypto API

Native cryptographic hashing and random generation.

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The `crypto.subtle` and `crypto.getRandomValues()` APIs provide secure, hardware-accelerated cryptographic primitives natively in browsers and Node.

js
const bytes = new Uint8Array(32);
crypto.getRandomValues(bytes);
const hash = await crypto.subtle.digest("SHA-256", bytes);

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  2. 2. Re-read the code snippets and say out loud what each line does.
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Check your understanding

  1. 1. Which function generates cryptographically secure random bytes?

  2. 2. Why must Math.random() NEVER be used for key or token generation?

  3. 3. What does crypto.subtle.digest() return?

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