Inside the Secure Exclave: what actually stays on your wrist
Apple's core claim is that raw audio for Siri Recap never leaves the Secure Exclave, a hardware-isolated compartment on the S11 chip that the operating system, apps, the user, and even Apple cannot reach [2]. That part checks out on paper - no audio is recorded or stored. But the feature does not stop at the wrist. A condensed, encrypted text version of the conversation, described as less than half the length of the original transcript, is sent off-device to Apple's Private Cloud Compute servers to generate the actual summary [3]. That data must be decrypted server-side to be processed, which independent analysis calls distinctly less secure than purely on-device handling [3]. So 'your conversation never leaves the device' is true only for the audio waveform, not for its textual content. The contrast with Live Rewind sharpens the picture: Live Rewind sounds an audible chime and lets the wearer glance back at 15 seconds of prior speech via the Digital Crown, while Siri Recap runs completely silently, with no signal to anyone nearby that a summary is being generated [4].



