Exam 312-50v12 topic 1 question 160 discussion

You are a cybersecurity professional managing cryptographic systems for a global corporation. The company uses a mix of Elliptic Curve Cryptography (ECC) for key exchange and symmetric encryption algorithms for data encryption. The time complexity of ECC key pair generation is O(n^3), where 'n' is the size of the key. An advanced threat actor group has a quantum computer that can potentially break ECC with a time complexity of O((log n)^2). Given that the ECC key size is 'n=512' and varying symmetric encryption algorithms and key sizes, which scenario would provide the best balance of security and performance?