Final answer:
The Bell-LaPadula security model is designed to maintain data confidentiality by implementing access control rules that prevent unauthorized information access, such as 'no read up, no write down' to protect sensitive data.
Step-by-step explanation:
The security model that addresses data confidentiality is the Bell-LaPadula model. This model is primarily focused on maintaining the confidentiality of information. It is based on a set of access control rules which prevent unauthorized access to data. The key concept in Bell-LaPadula is the 'no read up, no write down' rule, meaning a user cannot read data at a higher security level than their own, and cannot write data to a lower security level, thus preventing potential leaks of sensitive information.