SHORT SECURITY AUDIT REPORT Shamir Secret Sharing Implementation Bitaps JsBTC / PyBTC A. Modulo 255 Defect (“Never 255 Bug”) Polynomial coefficients never take the value 255 (0xFF) due to generator constraints (e.g., modulo 255 arithmetic or specific GF table usage). Impact: 1. The coefficient space is reduced from 256 to 255 possible values 2. Entropy reduction is extremely small Risk Assessment: 1. Severity: Low 2. Status: Non-fatal and does not reduce the Shamir threshold B. Global Polynomial Coefficients (Static Across Bytes) The polynomial coefficients (a₁, a₂, etc.) are generated once and reused across all bytes of the mnemonic entropy, instead of being regenerated independently per byte. Impact: 1. Secret bytes become correlated 2. Polynomials are no longer independent per byte 3. Shamir Secret Sharing security is significantly degraded Status: Design-level fatal flaw My addres BTC 18FXF47XcP52vhdbjimQ3CvD93NnHTPF73 Thankyou

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