What is a significant drawback of symmetric encryption?

The significant drawback of symmetric encryption is that it requires secure key distribution. In symmetric encryption, the same key is used for both encryption and decryption processes. Therefore, both parties communicating securely must have access to the same secret key. The challenge lies in the secure exchange of that key; if the key is intercepted by an unauthorized party during distribution, the entire encrypted communication can be compromised.

This requirement for a secure key distribution mechanism can lead to vulnerabilities, especially in large-scale systems where numerous users and keys may be involved. As a result, managing and protecting keys can become complex and poses risks in terms of ensuring confidentiality, integrity, and authenticity of the communications.

While symmetric encryption is generally faster and more efficient for encrypting large amounts of data compared to asymmetric encryption, and it is not too complex for practical use, the key distribution issue remains a critical concern that limits the scalability and security of symmetric encryption implementations.