Is it true that if cydia lists "6.1.2" as in my image, the SHSH for 6.1.2 has been saved by Cydia for me?
How do I access this SHSH later if I need to restore?
I tried tinyumbrella but it wouldn't work for 6.1.2
TU hasn't been updated yet.
Use iFaith instead, its been updated to support 6.1.2.
I might be wrong, but I don't think iFaith supports the iPhone 5 yet. So I think you'd be out of luck if Apple fixes the jailbreak exploits and you need to restore.
yeah, but does that image show that Cydia saved my SHSH already?
I was under the impression I had to restore to a clean 6.1.2 and save my SHSH before jailbreaking. Since I am already jailbroken, I don't want to restore my phone again to use iFaith.
Yup that means your shsh has been saved on cydias servers.
Just as long as you updated to 6.1.2 via iTunes and not OTA then your good to go, you can use iFaith right now to save your SHSH to your computer, even if your already jailbroken.
Is it true that if cydia lists "6.1.2" as in my image, the SHSH for 6.1.2 has been saved by Cydia for me?
Yes
How do I access this SHSH later if I need to restore?
Tools do remote access or you can pull it from Cydia server
I tried tinyumbrella but it wouldn't work for 6.1.2
It hasn't been updated for 6.1.2 yet
When the devs develop a method of re-restoring and downgrade the A5 and A6 devices on 6.x you can use redsn0w to downgrade or re-restore with the Cydia stored SHSH's. You'll have to use "remote" SHSH's in the process, which is the Cydia SHSH's
Once TU is updated you can save 6.1.2 SHSH's directly or request them from Cydia (advanced tab)
For A5 and A6 devices as iFaith is concerned it can only fetch the SHSH's and submit them to Cydia. The SHSH's cannot be used to restore a previous firmware or re-restore non-signed firmware. iFaith use the limera1n exploit wihich only works on A4/3GS.
So in summary you can restore an iPhone 4 with SHSH saved up to 6.1.2 and restore with redsn0w and jailbreak using evasi0n?