French developers have reverse engineered the Siri feature of Apple’s iPhone 4S, to run it on other devices
A group of mobile application developers have cracked Siri, the “personal assistant” software touted as one of the main draws of Apple’s recently released iPhone 4S, allowing the feature to be used on other devices.
French software developers Applidium said they had successfully reverse-engineered the techniques that the iPhone 4S uses to interact with the Siri service, and that they had successfully run a speech-to-text query from another device.
Home Made Applications
“Today, we managed to crack open Siri’s protocol,” Applidium’s developers wrote in a blog post, “As a result, we are able to use Siri’s recognition engine from any device.”
The firm said that developers could write an Android or iPad application that uses Siri and has released a collection of tools written to help understand Siri’s protocols written in Ruby, C and Objective-C.
“Those aren’t really finished, but should be very sufficient for anyone technically inclined to write a Siri-enabled application,” Applidium said.
The catch is that Siri requires a valid iPhone 4S identifier to function, meaning that while an iPhone 4S user could potentially use Siri on other devices, home-made Siri applications are unlikely to become widespread as Apple could easily disable iPhone 4S identifiers that appear to be being misused.
“Apple could blacklist an identifier, but as long as you’re keeping it for personal use, that should be allright,” the developers wrote.
The firm cracked Siri by creating its own HTTPS server, signed using a SSL certificate authority the firm set up itself, and identifying itself as “guzzoni.apple.com”, the server Apple uses to communicate with Siri devices.
Applidium found that the iPhone 4S sends raw audio data to this server, compressed using an audio codec called Speex that is designed for IP telephony. The protocol includes large amounts of extra information that is passed back and forth between the handset and the server.
“For example, when you’re using text-to-speech, Apple’s server even replies a confidence score and the timestamp of each word,” the developers wrote.
Android developers have already released a challenger to Siri called Iris, adding to the voice control options Google has offered since August 2010.
Iris is designed to add Siri-like features that Google’s earlier Voice Actions lacked, such as the ability to draw on contextual information including a user’s current location.