What is the term for methods that allow parties to compute a function over their inputs while keeping those inputs private?

The term that refers to methods allowing multiple parties to compute a function over their inputs while keeping those inputs private is known as Secure Multi-Party Computation (MPC). This cryptographic protocol enables separate parties to collaborate on a computation, such as calculating a sum or a product, without revealing their individual inputs to each other.

The key aspect of Secure Multi-Party Computation is that even though the parties jointly compute a result, none of them gain access to the other parties’ private data. This is particularly useful in scenarios where privacy is crucial, such as in finance or personal data management.

In contrast, Distributed Ledger Technology focuses on recording data across multiple locations securely, allowing for transparency and immutability, but it does not inherently focus on the privacy of inputs during computation. Private Key Cryptography deals with symmetrical key encryption, which uses the same key for both encryption and decryption and does not specifically address the privacy of inputs during collaborative computations. Public Key Infrastructure involves a framework for managing digital certificates and public-key encryption but also does not pertain directly to the computation of functions over private inputs.

Thus, Secure Multi-Party Computation uniquely fits the definition in the question by emphasizing both collaboration and privacy, making it the correct term.