| There's concept similar to what you're describing called crypto-shredding[1]. Hashing isn't a good way ensure the confidentiality of data--just the authenticity--you really want to prefer a solid cryptographic algorithm if your goal is to ensure data remains confidential. The idea behind crypto shredding is that you have a cryptographic key for each entity in your system and you use that key encrypt all fields for a given record. When it comes time to delete that data, you simply discard the key used to encrypt it. Assuming you've used reasonably good cryptography, this data is now effectively gone. This is useful in cases where: * You need to support the right to be forgotten (as defined in the CCPA[2] or GDPR[3]), since all you need to do to "delete" a user's data is to delete the key used to encrypt. * The data you need to delete exists across multiple data stores/applications/environments and ensuring consistency for the deletion across all these places is difficult. For example: You may have DB backups, long-lived caches, or 3rd party services/vendors that may have copies of this data. * You want to discard some, but not all, of a user's data. This is important in cases you're required by law to retain specific kinds of information even after a person has required it's deletion. For example, banking and finance companies are required to keep specific records about who they sent money to or performed services for. 1. https://en.wikipedia.org/wiki/Crypto-shredding 2. https://www.oag.ca.gov/privacy/ccpa 3. https://en.wikipedia.org/wiki/General_Data_Protection_Regula... |