# Mathematical Explanation for Varying Runtimes and Precision at 256-bit Security Levels in Threshold FHE

**URL:** <https://openfhe.discourse.group/t/mathematical-explanation-for-varying-runtimes-and-precision-at-256-bit-security-levels-in-threshold-fhe/1270>\
**Category:** FHE Questions\
**Created:** [May 15, 2024, 2:03pm UTC](https://openfhe.discourse.group/t/mathematical-explanation-for-varying-runtimes-and-precision-at-256-bit-security-levels-in-threshold-fhe/1270 "2024-05-15T14:03:39Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![ypolyakov](https://yyz1.discourse-cdn.com/flex031/user_avatar/openfhe.discourse.group/ypolyakov/32/47_2.png) [@ypolyakov](https://openfhe.discourse.group/u/ypolyakov)\
**Post date:** [May 16, 2024, 9:57pm UTC](https://openfhe.discourse.group/t/mathematical-explanation-for-varying-runtimes-and-precision-at-256-bit-security-levels-in-threshold-fhe/1270/4 "2024-05-16T21:57:08Z")

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The logic is very similar to what is described in [In which scenario does the decrease in Q result in reduced ring dimension?](https://openfhe.discourse.group/t/in-which-scenario-does-the-decrease-in-q-result-in-reduced-ring-dimension/1274) It is all driven by the security tables.

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