The use of a cryptographically-secure hashing algorithm is a method of transforming data into a different format through a process that makes it challenging to reverse-engineer or decode without a key. This technique is a form of obfuscation, which aims to make data less identifiable or understandable to unauthorized users. By applying obfuscation, the privacy engineer ensures that even if the hashed data is exposed, it does not reveal the actual personal data, thus protecting individuals' identities. This concept is supported by various privacy engineering practices that emphasize the importance of data transformation to protect privacy, as outlined in the IAPP Information Privacy Technologist documents.