[Q&A] What is an ECID SHSH? What is an iBSS/iBEC? How can I downgrade from 3.1?

[TheHeadFL]

If you are asking any of those questions, the answer is you cannot downgrade to 3.0.

If you had a 3.0 SHSH on file with Cydia, you would know about it, because you would have had to read about it in Cydia when you did it.

In short, if you don't know what a 3.0 SHSH is, you don't have one.

[Buddha321]

And may I add one more thing. Even if you're sure you have ECID hashed on Cydia, before you do anything to your phone,

MAKE SURE IT SAID 3.0 FIRST!!

You click the button while you're on FW3.0/3.0.1 doesn't mean you have the 3.0/3.0.1 ECID on file, if it's after the cutoff, you'll ONLY get a 3.1 ECID SHSH.

[MegaGoo]

in regards to the files needed to restore down to 3.0 from apple (non jailbroken) 3.1 on a 3GS, the only way you will have either 1) the tmp files you need or 2) the 3.0 blob is if you either 1) made backup copies of the tmp files during a 3.0 install perior to 9/9/2009, or 2) clicked "make my life easier" in cydia between appx 9/6/2009 to 9/9/2009

[TheHeadFL]

Bump for all the n00bs. Hundreds of threads about this.