Worked on the openssl/openssl repository to address cryptographic correctness issues in the AES-GCM implementation for PPC64 architectures. Focused on fixing integer truncation by updating local variables from int to size_t, ensuring accurate nonce and length handling for large inputs. Improved error propagation in the decryption path to prevent silent failures, enhancing data integrity for production cryptographic operations. All changes were implemented in C with a strong emphasis on low-level programming and cryptography. The fixes were validated through comprehensive EVP/cipher tests on POWER8 hardware, resulting in reliable performance and improved safety for cryptographic primitives in real-world deployments.