Request for References on `EstimateLogP` Method

Library Questions
1

Hello,

I’ve been trying to correctly set the ring dimension, and while investigating, I came across Commit 4eed808(link), which mentions:

Fix logQ(P) estimation used for finding the minimum ring dimension

I noticed that a new method, EstimateLogP, was introduced as part of this update. This seems quite important for understanding how the estimation is now done.

Would there happen to be any references or documentation that explain the theoretical background or derivation behind EstimateLogP? I’d really appreciate any pointers to papers, notes, or internal rationale behind this change.

Also, if there are any other related changes or context introduced in this commit that might be useful for understanding how ring dimension estimation has evolved, I’d be very grateful if you could point me to those as well.

Thanks in advance!

2

The underlying ideas and noise estimation expressions are described in Revisiting Homomorphic Encryption Schemes for Finite Fields (Appendix B - hybrid key switching). The purpose of EstimateLogP is to properly estimate \log Q P before the actual moduli for Q and P are known/generated. This \log Q P is then used to find the minimum secure ring dimension using the (R)LWE guidelines/tables presented in Homomorphic Encryption Standard and Security Guidelines for Implementing Homomorphic Encryption