--- title: Medium | daily.dev description: Computers are deterministic machines that cannot generate true randomness on their own. Pseudo Random Number Generators (PRNGs) use a seed and formula, making... canonical: https://daily.dev/posts/medium-yqrq542nr twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Medium | daily.dev og:description: Computers are deterministic machines that cannot generate true randomness on their own. Pseudo Random Number Generators (PRNGs) use a seed and formula, making... og:url: https://daily.dev/posts/medium-yqrq542nr og:image: https://api.daily.dev/og/posts/yqRq542nr.png og:image:alt: Medium og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Medium **[Medium](https://daily.dev/sources/medium_js)** · 5 min read · 0 upvotes · 0 comments ## Summary Computers are deterministic machines that cannot generate true randomness on their own. Pseudo Random Number Generators (PRNGs) use a seed and formula, making them predictable if an attacker knows those values. The solution is entropy: collecting chaotic real-world data (temperature, noise, photons) via hardware sensors into an OS entropy pool, which is then hashed to produce unpredictable random numbers. This approach is used in high-security applications like web3 private key generation and password salting. The avalanche effect in hashing and frequent key destruction make the output practically unbreakable. Interestingly, humans are also poor at true randomness due to cognitive biases, making computers with entropy pools arguably more random than people. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How do computers generate truly random numbers if they are deterministic machines? Computers rely on pseudo-random number generators that use a seed and formula, which is deterministic and theoretically predictable if an attacker knows both. To achieve secure randomness, operating systems collect real-world chaotic data such as heat, photon noise, or traffic timing into an entropy pool, hash it, and combine it with a nonce counter to produce unpredictable output used for private keys and password salts. _Developers securing key generation or password salts can dig deeper into entropy pool design on daily.dev._ ### Why does Cloudflare use lava lamps for encryption? Cloudflare uses a wall of lava lamps as a source of real-world chaotic visual data, captured by cameras and fed into an entropy pool to help generate secure random numbers for encrypting internet connections. The unpredictable, ever-changing patterns of the lava lamps provide entropy that a purely mathematical formula alone could not guarantee. _Anyone comparing entropy sources for cryptographic randomness can track examples like this on daily.dev._ ## Similar posts on daily.dev - [The Futility of Lava Lamps: What Random Really Means](https://daily.dev/posts/the-futility-of-lava-lamps-what-random-really-means-tb2egqxlu) · Lobsters · 0 upvotes · 0 comments - [Random Number Generator Uses Camera Noise](https://daily.dev/posts/random-number-generator-uses-camera-noise-x7lhludbs) · Hackaday · 0 upvotes · 0 comments - [Certifiably random: Swiss researchers claim perfect random number source](https://daily.dev/posts/certifiably-random-swiss-researchers-claim-perfect-random-number-source-t6hhqkb2o) · CSO Online · 0 upvotes · 0 comments --- Tags: [#security](https://daily.dev/tags/security), [#cryptography](https://daily.dev/tags/cryptography) [View this post on daily.dev](https://daily.dev/posts/medium-yqrq542nr) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Medium","url":"https://daily.dev/posts/medium-yqrq542nr","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/medium-yqrq542nr"},"datePublished":"2026-07-17T20:56:30.116Z","dateModified":"2026-09-14T09:27:28.234Z","description":"Computers are deterministic machines that cannot generate true randomness on their own. 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