Ever since rumors of an impending Siri port started circulating, non-iPhone 4S owners have been wondering why Siri can’t be made available on older iDevices. We’ve seen video of hackers running Siri on the iPhone 4, iPod touch 4G, iPhone 3GS, and even video of Siri controlling random devices, like a thermostat.

While these specific instances show that Siri can indeed run on non-4S devices, publicly distributing Siri poses a whole other set of problems. The complex system that Apple’s servers use to authenticate with Siri on the iPhone 4S is one of the main reasons that a Siri port can’t be made available to everyone at the moment.

A developer that goes by the name of “n00neimp0rtant” has detailed why he, or anyone else, cannot release a Siri port. On the ModMyi forums, he includes a video of Siri working on his iPod for proof.

A development firm called Applidium recently hacked Siri’s security protocol and made the findings available for everyone to access online. Since then, another hacker has created a Siri proxy sever that allows anyone with the appropriate knowledge to make Siri interact with non-Apple devices. When Siri connects with Apple to process requests, a multi-level series of authentications takes place.

Here’s how the authentication with Apple’s servers works, as explained by n00neimporant:

Authentication relies on four pieces of information to identify and validate the device as an iPhone 4S: three separate identifiers that appear to be somehow tied to the device, and a chunk of “validation data” generated by the 4S. As I don’t have access to a jailbroken 4S, I used Applidium’s scripts to grab this data from a 4S, then I made a tweak that “fools” my iPod into using that same exact data.

Not only does Siri require an iPhone 4S unique identifier, but the servers are smart enough to recognize a faked connection after 24 hours:

Apple designed the system so that every chunk of validation data only authenticates successfully with their servers for 24 hours. After that, the data becomes invalid, and my iPod just goes right back to apologizing for not being able to connect to the network.

The iPod doesn’t cause it to expire; the server just stops accepting that data as “valid” after 24 hours.

Essentially, running Siri on a non-4S device requires access to a iPhone 4S, effectively making the port useless for people that don’t own Apple’s latest smartphone.

The code used by the 4S to generate validation data cannot run on any other device and is highly obfuscated (intentionally made very difficult to trace or reverse-engineer).

There are more networking problems that make a Siri port problematic, including the fact that no two devices can use the same identifiers/validation data to run Siri at the same time. Essentially, if you’re using an iPhone 4S’s unique identifier to run Siri on an unsupported device, the voice technology won’t work on the iPhone 4S that is acting as the host for the other device.

Finally, n00neimportant explains how a Siri port would theoretically be distributed legally. He compares the distribution to the way that jailbreak tools like PwnageTool handle copyrighted software:

First off, without question, a method by which one could generate his/her own validation data as needed would need to be developed first. That in itself is very unlikely, but it would be required for a releasable Siri port.

But what about the “legal” part? Think for a moment about PwnageTool: it is 100% legal because it does not contain any copyrighted material. You have to provide PwnageTool with any and all iPhone software update data and it does all necessary patching on-the-fly, rather than coming bundled with pre-patched data. Now envision for a moment an app for a jailbroken 4S that would package up all of the Siri files from its own filesystem into a single .deb, installable on any of your own personal iOS devices. Such a solution would avoid any piracy complications by removing the need to actually distribute the copyrighted Siri binaries and graphics; the only downside is you would legally need your own 4S from which to gather the Siri files. Yes, it’s not ideal, but it would be the only legal way for a Siri port to be released.

Hopefully that clears the air. And in case you didn’t know, Apple itself has said that it has “no plans” to bring Siri to other iDevices.

[Thanks for the tip, Steven!]

  • iSad 🙁

  • Anonymous

    Siri is cool…… but its not cool enough to upgrade to a 4S.

    • i agree
      esspecially if you are NON AMERICAN 4S user.
      SIRI is at the moment just for the American of English people usefull

  • That guy has no idea what he’s talking about. Two weeks ago he was asking me for my Siri GUI files and now suddenly he’s an expert on the subject? When there’s a will there’s a way. A workaround will be developed to bypass the server validation altogether.

    • Anonymous

      Which guy, may I ask?

    • Anonymous

      n00neimp0rtant created OpenNotifier for iOS 4, so he’s actually a pretty good dev, and what he has discovered about the Siri port unfortunately makes sense. How can the device ever bypass the server validation, when 100% of Siri processing is done on the server itself? (and if it doesn’t pass a set of 3 differently generated UDIDs that change every 24 hours it will fail).

      As far as him asking you for the GUI files, that would probably be just so he had the official graphics to match the code.

  • Hopefully it will appear in the next-gen devices. And hopefully devs can integrate it with their apps. i.e. open Facebook, open Angry Birds, open the camera, etc. etc.

  • Dan

    maybe they can stop screwing around with Siri now and release a untethered jailbreak for OS5! They’ve just been bragging for months on how it was almost resolved…

  • Benjamin Hoover

    Instead of grabbing the files from the 4s couldn’t they just grab it from the firmware? Or would that be illegal?

  • this is cool!!

  • Anonymous

    People, download WolframAlpha. As easy as that. It doesn’t have voice recognition, but then again, would you actually use it?

    Siri IS WolframAlpha.

    • People use Siri for fun or other things people tend to tske out their calaculators when is comes to math

      • Anonymous

        You obviously haven’t used WolframAlpha. If you think it’s only a huge mathematical brain, you’re wrong. Siri IS BASED on it. And WolframAlpha does have that sarcastic sense of humor as well.

  • this is great. I know I have an iphone 4 and my wife an i4s. Although not as many people could benefit from this there are quite a few I bet that have access to a i4s but themselves have an i4. This problem will definitely be around for at least another 2 years for all those that bought the cheaper i4 at the i4s launch or bought the i4 right before the launch.

  • It /is/ actually possible to make a port. A custom IPSW containing the Siri files would need to be made by the user with PwnageTool or sn0wbreeze. It would be built from the user’s device IPSW and a separate 4S IPSW. The only problem then is non-4S-owners will be restricted to using third-party servers instead of the official Siri servers (due to the 4S UDID restriction).


  • Can’t they just host a ‘Siri’ server rather than connecting to Apple’s own?

    Also, where’s the Untethered Jailbreak? Been waiting for a month and still nothing. And yes I understand that it takes LONG, but it seems the Dev team is more focused on porting Siri to non-iPhone 4S devices.

    • The most important thing right now is an IOS5 Jailbreak for devises running with the A5 processor. I don’t own an iPad 2 or iPhone 4S but see the need to get a Jailbreak on these devises.

      The Semi Untether Jailbreak for iPhone 4 is not as big a pain as many people think. I have had it now for about a month and only had to reboot my phone once in this time. Try it!!!

      • Didn’t they find couple of iOS 5 Exploits? If so, these A5 Based Devices can be Jailbroken? The only Untethered Device is the iPhone 3GS (Old Bootrom).

        I don’t want to deal with the Tethered Jailbreak again. When I updated to iOS 5, I opened Cydia then It said ‘Preparing File System’ then few seconds later, It did a respring and when I unlocked my phone, my ‘Messages’, ‘Phone’, ‘Mail’ etc; were missing. Plus, I can’t access Cydia, It just kept crashing. So I did a reboot and still the same issue. I restored again the second time and still had this issue. The third time, I went ahead and launched TinyUmbrella and downgraded back to iOS 4.3.3 (which I am currently on). It works for you guys, but I seem to have bad luck with this. I can wait a bit longer for a Untethered Jailbreak, but it needs to come soon.

  • Anonymous

    I am sure that there are people, that after reading this article, still dream about having Siri outside the iPhone 4S without an UID. IDIOTS!

  • The community is all broken up. I don’t see a jailbreak any time soon. Let alone the iPhone 5. Things have gotten way tough and the people that could/would are REALLY out of the game (GeoHot, Comex, ionic).

    There is a jailbreak for the 4s and a Siri port… It exists… In videos from the prominent jailbreak community members. What do the people have? NOTHING!

    The lack of a jailbreak is what prompted me to return my 4s and get a skyrocket.

    Compared to the 4S it is CRAP, but…. I can do what I can’t with the 4s since there is NO jailbreak for the 4s.