Apple is rolling out an innovative privacy-preserving search feature in iOS 18's Photos app, powered by homomorphic encryption technology. This groundbreaking implementation allows users to search their photo libraries with unprecedented accuracy while maintaining strict privacy controls.
The new system, codenamed "Wally," enables sophisticated image recognition and search capabilities without exposing the actual content of users' photos to Apple's servers. When a user searches for photos, like "golden retriever," the Photos app creates an encrypted mathematical representation of the search query that Apple's servers can process without decrypting.
"This is a major advancement in protecting user privacy while delivering powerful search features," notes security researcher Jeff Johnson, who first identified the technology's implementation in iOS 18.
The technical approach uses "somewhat homomorphic encryption" (SHE), which allows Apple's servers to perform limited mathematical operations on encrypted data. This means search queries can be processed without Apple ever seeing the actual content or search terms.
To optimize performance, Apple employs a hybrid approach:
- Photos are grouped into encrypted clusters based on similar characteristics
- Search queries are anonymized through a third-party proxy network
- Results are returned in encrypted form that only the user's device can decode
While the technology represents a step forward for privacy, some experts have raised questions about the system's reliance on Apple's cloud infrastructure. The company maintains that the mathematical foundations of homomorphic encryption provide cryptographic guarantees of privacy.
The feature will be available to all iOS 18 users when it launches later this year. Apple emphasizes that users will have full control over enabling or disabling the enhanced search capabilities.
This implementation showcases how advanced cryptography can help balance powerful features with strong privacy protections - a challenge that has long faced technology companies handling sensitive user data.