Interactive demonstrations of the privacy-preserving architecture that makes Prism different from traditional content filters.
No matter which layer handles your request, your privacy is always protected.
Handles most websites
Most websites are checked instantly on your device without any data leaving your phone.
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For some websites
When needed, we check securely through encryption. No one can see what website you're visiting.
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For unclear cases
For tricky websites, smart technology on your device makes the decision. Everything stays private.
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Traditional filters promise not to look at your browsing data. Prism makes it cryptographically impossible to look. It's not trust—it's math.
See how Prism checks URLs in under a millisecond—all on your device, with zero network requests.
Try these examples:
Each URL is hashed to multiple positions in the bit array. If all positions are set, the URL might be blocked.
How it works: The Bloom filter uses multiple hash functions to map each URL to positions in a bit array.
Privacy guarantee: This check happens entirely on your device. No data is sent to any server.
Performance: Bloom filters can check millions of URLs in under a millisecond with minimal memory usage.
False positives: Bloom filters may occasionally flag a safe URL as potentially blocked (triggers PIR check), but will never miss a blocked URL.
When the Bloom filter needs clarification, PIR ensures your query stays private through cryptographic guarantees.
Strips IP address
Processes encrypted query
Your device encrypts the URL query with a key only you have
Query is routed through Apple's OHTTP relay, which strips your IP address
Server processes the encrypted query without ever decrypting it
Server returns encrypted result. Only your device can decrypt it