What does RSA primarily use for?

RSA primarily uses asymmetric encryption and the creation of digital signatures, which are fundamental components of public key cryptography.

Asymmetric encryption allows secure communication by using a pair of keys: a public key for encrypting data and a private key for decrypting it. This method ensures that even if the public key is widely disseminated, only the holder of the private key can decrypt messages intended for them, thus providing confidentiality and security.

Additionally, RSA is also utilized for creating digital signatures. A digital signature ensures the integrity and authenticity of a message. When a sender signs a message with their private key, anyone with access to the sender's public key can verify that the message was indeed sent by the verified individual and has not been altered in transit. This application is especially important in securing online communications and transactions.

The other options, while relevant to data security and transmission, do not encapsulate the primary functions of RSA as focused on asymmetric encryption and digital signatures.