Final answer:
The service framework required to support large-scale public key-based technologies is the Public Key Infrastructure (PKI), which manages digital certificates and encryption keys to secure electronic communications.
Step-by-step explanation:
The service framework needed to support large-scale public key-based technologies is known as Public Key Infrastructure (PKI). PKI is a set of policies, roles, hardware, software, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates and manage public-key encryption. The purpose of a PKI is to facilitate the secure electronic transfer of information for a range of network activities such as e-commerce, internet banking, and confidential email. It provides a level of trust and security by issuing digital certificates ensuring the identity of individuals and devices. While options like HMAC and RSA are important components of cryptographic systems, PKI provides the overarching framework necessary for a large-scale deployment of public key technologies. HMAC is a type of message authentication code using a cryptographic hash function coupled with a secret key, and RSA is an algorithm used to encrypt and decrypt messages.