In which scenario is symmetric cryptography typically preferred?

Symmetric cryptography is typically preferred when quick encryption and decryption are required. This approach employs the same key for both encryption and decryption, which allows for fast processing speeds. As symmetric algorithms generally operate with less computational overhead compared to asymmetric algorithms, they can efficiently handle large volumes of data in real-time applications. This performance advantage makes symmetric cryptography particularly suitable for scenarios where rapid encoding and decoding are essential, such as securing data in transit or during bulk data storage.

In terms of the other scenarios presented, symmetric cryptography is not necessarily ideal. For example, if data needs to be accessible to everyone, symmetric keys pose a challenge as they must be securely shared among all parties involved, which may compromise security. In scenarios demanding secure key exchange, asymmetric cryptography is more advantageous since it utilizes public and private key pairs to facilitate secure exchanges without the need for sharing a common secret. Lastly, when a public key is available to everyone, this aligns more with asymmetric cryptography, where the public key can be distributed for secure communications, while the private key remains confidential.