WIRED: MongoDB Debuts ‘Queryable Encryption’ to Fight Hacks and Leaks.
[1]https://www.wired.com/story/mongodb-queryable-encryption-databases

   "After years of data breaches, leaks, and hacks leaving the world
   desperate for tools to stem the illicit flow of sensitive personal
   data, a key advance has appeared on the horizon.

   "On Tuesday, MongoDB is [2]announcing “Queryable Encryption,” a feature
   that will allow database users to search their data while it remains
   encrypted. The tool, which is debuting in preview as part of MongoDB
   6.0, attempts to bridge academic cryptography findings and real-world
   environments so users can adopt the feature without needing advanced
   theoretical expertise. Crucially, Queryable Encryption is built to work
   with existing databases rather than requiring users to re-architect
   their systems before they can take advantage of it.

References

   1. https://www.wired.com/story/mongodb-queryable-encryption-databases
   2. https://www.mongodb.com/blog/post/mongodb-releases-queryable-encryption-preview