Public key validation is the process of verifying that a cryptographic public key is authentic, properly formatted, and safe to use. This step ensures the key has not been tampered with, is mathematically valid, and actually belongs to the claimed entity. Validation typically checks that the key falls within the correct parameters for its algorithm (such as length and structure), and that it is not a known weak or compromised key. Proper public key validation is crucial to prevent security breaches, such as man-in-the-middle attacks or unauthorized access, by ensuring only legitimate keys are trusted for operations like encryption, signature verification, or secure communication.