# Parameters Value/Noise Tolerance according to \\alpha-HE scheme

**URL:** <https://openfhe.discourse.group/t/parameters-value-noise-tolerance-according-to-alpha-he-scheme/1008>\
**Category:** FHE Questions\
**Tags:** questions, openfhe-help\
**Created:** [January 7, 2024, 11:51am UTC](https://openfhe.discourse.group/t/parameters-value-noise-tolerance-according-to-alpha-he-scheme/1008 "2024-01-07T11:51:06Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Atwo](https://avatars.discourse-cdn.com/v4/letter/a/e99b99/32.png) [@Atwo](https://openfhe.discourse.group/u/Atwo)\
**Post date:** [January 7, 2024, 11:51am UTC](https://openfhe.discourse.group/t/parameters-value-noise-tolerance-according-to-alpha-he-scheme/1008/1 "2024-01-07T11:51:06Z")

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Hi,

How much noise we can apply in a system so that system keep remain in \alpha-homomorphic encryption. Otherwise after adding extra noise or increasing parameter values it will destroy the scheme.  
Where \alpha belongs to {Somewhat, Partial, Leveled}.  
In short what is the percentage handled by alpha.  
Can you share any resource ?

Thanks in advance 🙂

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<div class="post-metadata">

**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:** [January 8, 2024, 10:53pm UTC](https://openfhe.discourse.group/t/parameters-value-noise-tolerance-according-to-alpha-he-scheme/1008/2 "2024-01-08T22:53:36Z")

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The answer depends on the scheme and performed computations (the “circuit”). For instance, in BGV/BFV/CKKS the highest noise is incurred for multiplications. The multiplicative depth determines how many multiplications can be performed in a series.

For a conceptual introduction to BGV/BFV, you can watch the following webinar: [Homomorphic Encryption for OpenFHE Users – OpenFHE.org](https://www.openfhe.org/portfolio-item/homomorphic-encryption-for-palisade-users-3/)

If you are looking for a more advanced description of noise growth in BGV/BFV (for addition, multiplication, and other operations), I suggest reading [Revisiting Homomorphic Encryption Schemes for Finite Fields](https://eprint.iacr.org/2021/204)