lattigo: fix galois key generation for negative rotations - #3341
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AlexanderViand wants to merge 1 commit into
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lattigo: fix galois key generation for negative rotations#3341AlexanderViand wants to merge 1 commit into
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The galois element loop in ConfigureCryptoContext only multiplied for positive shifts, so negative rotation indices produced galoisElement = 1 and rotation failed at runtime. Reduce the shift mod 2N first, matching lattigo's Parameters.GaloisElement.
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j2kun
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Aug 17, 2026
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Lattigo's
ConfigureCryptoContextshould usenormalizeRotationon the rotation index first, otherwise negative rotations simply get galois element "1" since the loop was never entered.Fixes #3337