# Encryption: If it is based off prime numbers why not just have a great big list of prime numbers to break the codes?

**URL:** <https://boards.straightdope.com/t/encryption-if-it-is-based-off-prime-numbers-why-not-just-have-a-great-big-list-of-prime-numbers-to-break-the-codes/1026772>\
**Category:** Factual Questions\
**Created:** [January 17, 2026, 4:29pm UTC](https://boards.straightdope.com/t/encryption-if-it-is-based-off-prime-numbers-why-not-just-have-a-great-big-list-of-prime-numbers-to-break-the-codes/1026772 "2026-01-17T16:29:31Z")\
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**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\
**Post date:** [January 17, 2026, 5:10pm UTC](https://boards.straightdope.com/t/encryption-if-it-is-based-off-prime-numbers-why-not-just-have-a-great-big-list-of-prime-numbers-to-break-the-codes/1026772/5 "2026-01-17T17:10:16Z")

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For Christmas someone gave me the book below. I get a Mersenne Prime is a subset of all primes but still…it made me think we have a great big list of all primes. I would guess someone has the record for the biggest prime number ever found which means we have a list of all smaller primes.

> **[PXL 20260117 170259162 hosted at ImgBB](https://ibb.co/JFvCjYP1)**
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> Image PXL 20260117 170259162 hosted on ImgBB

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