Cydia

This article is about the iOS application. For the moth genus, see Cydia (genus).

Cydia

The Cydia homescreen on an iPod Touch 4G running iOS 5
Developer(s)	Jay Freeman (saurik)[1]
Initial release	February 2008; 3 years ago (February 2008)
Stable release	1.1.1 (March 26 2011) / 1.1.2 (July 5 2011) (For use with jailbreakme.com only)
Operating system	iOS
Available in	English, Italian, Spanish, Chinese, Greek, German, Hebrew and Dutch
Type	Graphical user interface, Package manager
License	Open source
Website	http://cydia.saurik.com/

Cydia (pronounced /sɪˈdi.ə/) is a graphical user interface for a distribution of the Advanced Packaging Tool known as Telesphoreo.^[2] Telesphoreo is available for iOS, and enables a user to find and install software packages (including apps, interface customizations, and system extensions) on a jailbroken iPhone, iPod Touch or iPad. It is the main independent third-party digital distribution platform for software on iOS.^[3] Many of the software packages available through Telesphoreo are free, and it also includes several hundred packages for sale through the Cydia Store with a commission setup similar to the App Store.^[4] Most of these packages focus on providing customizations and modifications (often called "tweaks") that can only run on jailbroken devices (since the App Store is limited to distributing self-contained apps).^[5]

Cydia and Telesphoreo are developed by Jay Freeman (also known as "saurik") and his company, SaurikIT.^[1] The name "Cydia" is an allusion to the Codling Moth, with a scientific name of Cydia pomonella, which is the proverbial "worm in the apple."^[6]

Purpose and function

Cydia is a graphical user interface (GUI) available to jailbroken iOS users using APT repositories to install software unavailable on the App Store. Therefore Cydia is in turn, a GUI for dpkg. The version of APT that is packaged with the installation of Cydia, known as Telesphoreo, comes with a few trusted software repositories pre-installed known as "community sources." Many stable packages are available on these repositories; however, additional repositories can be easily added. This enables the iOS development scene to stay as open as possible; anyone with a server can set up, host, manage, and update his or her own repository and share it with the community. The community sources accept package submissions, which helps packages gain more exposure than if they were hosted on separate repositories.

Software packages are downloaded directly to an iOS device, to the same location as Apple's pre-installed applications (the /Applications directory). (Jailbroken devices can also still normally buy and download apps from the official App Store.^[7])

Cydia is generally installed automatically during the process of jailbreaking an iOS device.^[6]

Software available through Telesphoreo

Screenshot of a list of packages in Cydia; blue text indicates a paid package.

Some of the packages available using Cydia and Telesphoreo are standard applications, but the majority of the packages are extensions and modifications for the iOS interface and for apps in the iOS ecosystem. Since these software packages run on jailbroken devices, they can provide functionality outside the scope of normal applications — such as system-wide changes to the user interface, new features inserted into existing apps, customizations of button actions, extensions of networking behavior, and other "tweaks" to the system. Users install these for purposes including personalization and customization of the interface,^[8] adding desired features and fixing annoyances,^[9] and making development work on the device easier by providing access to the filesystem and command-line tools.^[10][11] Most of the packages available through Telesphoreo are written by independent developers.

Popular packages in Telesphoreo include Winterboard (which lets users "skin" the iOS interface and app icons with themes),^[12] MyWi (enable Wi-Fi tethering),^[5] SBSettings (access settings and controls with a gesture),^[13] Barrel (stylize the animated transition between SpringBoard pages),^[14] and DisplayOut (display the device's screen on a connected TV or monitor).^[15] Many extensions available through Telesphoreo are based on a framework called MobileSubstrate, developed by Freeman, which makes the process of writing and maintaining system modifications easier.^[6]

Since packages presented in Cydia are not limited by the iOS app security sandbox, journalists recommend using "the same vigilance you use when considering a program for your computer," including learning about the developer who wrote the package, before installing it.^[5]

Cydia Store

In March 2009, Freeman introduced a simple, unified payment system that allows developers to sell packages inside of Cydia (with user purchases linked to user accounts), much like the official App Store. Users may use Amazon Payments or PayPal to purchase items within Cydia.^[16] The proof of payment is linked to a Google or Facebook account in case users move to a new iOS device or restore the device; users can log in and install all their previously-purchased packages without having to buy them again.^[17]

Most of the packages for sale within Cydia use the Cydia Store payment system, with Cydia taking a 30% cut that includes covering PayPal fees and server costs.^[18] Developers are not required to use the Cydia Store system to charge for their software; some paid packages, such as LockInfo and biteSMS, must be registered separately from the Cydia Store through the developers' own means.

Firmware "signature" feature

In addition to offering software to install, in September 2009 Cydia was improved to help users have the option to downgrade (or upgrade) their device firmware to versions not currently allowed by Apple. Cydia caches the digital signatures known as SHSH blobs used by Apple to verify restores of the iOS firmware (which Apple uses to limit users to only installing the latest version of iOS).^[19] Cydia's storage mechanism enables users to downgrade their firmware to a previous version by means of a replay attack.^[20] This means, for example, that a person with a jailbroken device who upgrades to a non-jailbreakable version of iOS can choose to downgrade back to a jailbreakable version.^[21]

However, iOS 5 and later firmwares implement a new system that confirms the SHSH is the latest on Apple's servers every time the device is turned on, which makes it nearly impossible to perform a replay attack. This is because nobody outside of Apple knows their new private key that is used to confirm the SHSHes are genuine.^[22]

Jailbroken platform

Using Cydia and Telesphoreo depends on having a jailbroken device. Jailbreaking the iPhone was a legal grey area^[23] until July 2010, when the U.S. Copyright Office declared a Digital Millennium Copyright Act exemption making jailbreaking the iPhone legal.^[24] Apple policy is that jailbreaking voids the device warranty, and that unauthorized software can cause the device to be less stable.^[9]

Jailbreaking is normally done via applications on a computer such as redsn0w (or other tools), but a website named JailbreakMe was used for iOS 4.3.3 and jailbroke the iDevice through the web browser on the device itself (Safari).

History

Freeman first released Cydia in February 2008 as an open-source alternative to Installer.app on iPhone OS 1.1,^[25] but Telesphoreo quickly became the most popular package manager after iPhone OS 2.0's release in July 2008.

In August 2009, Freeman said "about 4 million, or 10 percent of the 40 million iPhone and iPod Touch owners to date, have installed Cydia."^[26]

In September 2010, Freeman's company, SaurikIT, LLC, announced that it had acquired Rock Your Phone, Inc. (makers of Rock.app), which made the Cydia Store the largest third-party app store for jailbroken iOS devices.^[27][28]

In December 2010, Freeman announced plans to also release a Cydia Store for Mac OS X as a supplement, not an alternative,^[29] to Apple's Mac App Store.^[30]

As of April 2011, Cydia had $10 million in annual revenue and 4.5 million weekly users, with $250,000 in profit after taxes annually.^[18]

References

1. ^ ^{a b} "Saurik's Homepage". http://www.saurik.com/. Retrieved August 4, 2010. 
2. ^ Freeman, Jay. "Bringing Debian APT to the iPhone". The Realm of the Avatar. http://www.saurik.com/id/1. Retrieved 2011-11-17. 
3. ^ Jack Loftus (September 11, 2010). "Largest iOS Jailbreak App Stores Become One After Cydia Acquires Rock". Gizmodo. http://gizmodo.com/5635633/largest-jailbreak-app-stores-become-one-after-cydia-acquires-rock. Retrieved August 2, 2011. 
4. ^ Yukari Iwatani Kane (March 6, 2009). "Breaking Apple's Grip on the iPhone". The Wall Street Journal. http://online.wsj.com/article/SB123629876097346481.html. Retrieved March 8, 2009. 
5. ^ ^{a b c} Thomas J. Fitzgerald (November 24, 2010). "Breaking Into the Smartphone (Risks Included)". New York Times. http://www.nytimes.com/2010/11/25/technology/personaltech/25basics.html?scp=1&sq=cydia&st=nyt. Retrieved August 2, 2011. 
6. ^ ^{a b c} Chris Foresman (December 13, 2010). "iPhone jailbreaker set to bring Cydia to Mac OS X". Infinite Loop. Ars Technica. http://arstechnica.com/apple/news/2010/12/iphone-jailbreaker-set-to-bring-cydia-to-mac-os-x.ars. Retrieved August 2, 2011. 
7. ^ Goodman, Danny (2010). Learning the IOS 4 SDK for JavaScript Programmers: Create Native Apps with Objective-C and Xcode. pp. 6–7. http://books.google.com/books?id=a09NMFdA6m0C&lpg=PA7&pg=PA6#v=onepage&q&f=false. 
8. ^ Adam Dachis (March 14, 2011). "How to Get the Most Out of Your Jailbroken iOS Device". Lifehacker. http://lifehacker.com/5781437/how-to-get-the-most-out-of-your-jailbroken-ios-device. Retrieved August 2, 2011. 
9. ^ ^{a b} Jenna Wortham (May 12, 2009). "Unofficial Software Incurs Apple's Wrath". The New York Times. http://www.nytimes.com/2009/05/13/technology/13jailbreak.html?pagewanted=all. Retrieved August 2, 2011. 
10. ^ Zdziarski, Jonathan (2008). iPhone Open Application Development: Write Native Applications Using the Open Source Tool Chain. pp. 3–4. http://books.google.com/books?id=fkXvibFJrpIC&lpg=PA3&dq=cydia%20-pomonella%20-moth&pg=PA3#v=onepage&q&f=false. 
11. ^ Landau, Ted (2009). Take control of your iPhone. p. 107. http://books.google.com/books?id=GiOVkVS4XZkC&lpg=PA109&dq=cydia%20iphone&pg=PA107#v=onepage&q&f=false. 
12. ^ Christopher Breen (December 26, 2008). "The best iPhone apps not in the App Store". Macworld. http://www.macworld.com/article/137767/2008/12/jailbrokenapps.html. Retrieved August 2, 2011. 
13. ^ Mike Keller (August 26, 2009). "No App Store, No Cry: Great Apps You'll Get Only By Jailbreaking Your iPhone". Geek Tech. PCWorld. http://www.pcworld.com/article/170847/no_app_store_no_cry_great_apps_youll_get_only_by_jailbreaking_your_iphone.html. Retrieved August 2, 2011. 
14. ^ Matt Brian (September 24, 2011). "Cydia and Jailbreak apps: The ecosystem, developers and increasing revenues". The Next Web. http://thenextweb.com/apple/2011/09/24/cydia-and-jailbreak-apps-the-ecosystem-developers-and-increasing-revenues/. Retrieved September 24, 2011. 
15. ^ Christopher Breen (January 31, 2011). "Projecting the iPad's entire interface". Macworld. http://www.macworld.com/article/157546/2011/01/project_ipad_jailbreak.html. Retrieved August 2, 2011. 
16. ^ Michael Rose. "Cydia Store now open for jailbreak app sales". The Unofficial Apple Weblog. http://www.tuaw.com/2009/03/09/cydia-store-now-open-for-jailbreak-app-sales/. Retrieved 2009-08-02. 
17. ^ Taimur Asad (January 20, 2011). "Cydia Adds "Manage Account" Feature, Which Shows Every App That Was Ever Purchased on Cydia". Redmond Pie. http://www.redmondpie.com/cydia-adds-manage-account-feature-which-shows-every-app-that-was-ever-purchased-on-cydia/. Retrieved August 2, 2011. 
18. ^ ^{a b} Ian Shapira (April 6, 2011). "Once the hobby of tech geeks, iPhone jailbreaking now a lucrative industry". The Washington Post. http://www.washingtonpost.com/business/economy/once-the-hobby-of-tech-geeks-iphone-jailbreaking-now-a-lucrative-industry/2011/04/01/AFBJ0VpC_story.html. Retrieved August 2, 2011. 
19. ^ Adam Dachis (April 25, 2011). "Save Your iDevice’s SHSH to Avoid Losing the Ability to Jailbreak". Lifehacker. http://lifehacker.com/5795242/save-your-idevices-shsh-to-avoid-losing-the-ability-to-jailbreak-your-idevice. Retrieved August 2, 2011. 
20. ^ Jay Freeman (saurik) (September 2009). "Caching Apple's Signature Server". saurik.com. http://www.saurik.com/id/12. Retrieved July 28, 2010. 
21. ^ Nat Futterman (May 25, 2010). "Jailbreaking the iPad: What You Need to Know". Geek Tech. PCWorld. http://www.pcworld.com/article/196492/jailbreaking_the_ipad_what_you_need_to_know.html. Retrieved August 2, 2011. 
22. ^ Oliver Haslam (June 27, 2011). "iOS 5 Will Halt SHSH Firmware Downgrades On iPhone, iPad, iPod touch". Redmond Pie. http://www.redmondpie.com/ios-5-will-halt-shsh-firmware-downgrades-on-iphone-ipad-ipod-touch/. Retrieved November 12, 2011. 
23. ^ Brian X. Chen (November 12, 2009). "Jailbreakers Battle Apple for Control of iPhone". Gadget Lab. Wired. http://www.wired.com/gadgetlab/2009/11/jailbreak-community/. Retrieved August 2, 2011. 
24. ^ David Kravets. "U.S. Declares iPhone Jailbreaking Legal, Over Apple’s Objections". Threat Level. Wired. http://www.wired.com/threatlevel/2010/07/feds-ok-iphone-jailbreaking/. Retrieved 2011-01-18. 
25. ^ Erica Sadun (February 28, 2008). "Debian-style installation arrives on iPhone". The Unofficial Apple Weblog. http://www.tuaw.com/2008/02/28/debian-style-installation-arrives-on-iphone/. Retrieved September 24, 2011. 
26. ^ Brian X. Chen (August 6, 2009). "Rejected By Apple, iPhone Developers Go Underground". Wired. http://www.wired.com/gadgetlab/2009/08/cydia-app-store/. Retrieved August 2, 2011. 
27. ^ Steven Sande (September 12, 2010). "Alliance of the jailbreakers: Cydia acquires Rock". The Unofficial Apple Weblog. http://www.tuaw.com/2010/09/11/alliance-of-the-jailbreakers-cydia-acquires-rock/. Retrieved August 2, 2011. 
28. ^ Jay Freeman (saurik). "Cydia += Rock Your Phone?". Cydia. http://cydia.saurik.com/faq/merger.html. 
29. ^ 8bitjay (December 20, 2010). "4 Things We Know So Far About Cydia for Mac". iSmashPhone. http://www.ismashphone.com/2010/12/things-we-know-so-far-about-cydia-for-mac.html. Retrieved August 2, 2011. 
30. ^ Steven Sande (December 10, 2010). "360 MacDev: Jay "saurik" Freeman on the jailbreak store for Mac apps". The Unofficial Apple Weblog. http://www.tuaw.com/2010/12/10/360-macdev-jay-saurik-freeman-on-the-jailbreak-store-for-mac/. Retrieved December 9, 2010. 

External links

• Cydia Facebook page