Which of the following is true about public-private key encryption in securing communications?

In public-private key encryption (asymmetric encryption), the public key is used by anyone to encrypt data, and only the corresponding private key holder can decrypt it. This ensures that the data remains confidential and can only be accessed by the intended recipient who holds the private key. The public key is openly shared, while the private key must be kept secret to ensure security. Option A is incorrect because the public key is not kept secret; it is used for encryption and is shared openly. Option B is incorrect because the private key is never shared; it is kept confidential. Option D is incorrect because public-private key pairs are used in asymmetric encryption, not symmetric encryption. Option E is incorrect because asymmetric encryption is not typically used for encrypting large files due to its computational complexity.