Downgrade 4.3.5 to 4.3.3

Hi, I've read a lot on the web and everyone says that it's impossible to downgrade from 4.3.5 to 4.3.3 without SHSH blobsbut I found a site which is

Downgrade 4.3.5 to 4.3.3 without SHSH Blobs - iPhone 4, 3GS, iPod Touch 4G, 3G, iPad - Jailbreak 4.3.5 / 5.1 / 4.3.1 / 4.3.2 / 4.3.3 / 4.3.4 iOS 5 Untethered - iPad 2 Jailbreak

They give the links for all necessary files and programs to download. (firmware versions, tiny umbrella, iFaith)
I'm a newbie with the iPhone and I was wondering if it's a good idea to follow those steps be able to downgrade and jailbreak or it's hazardous !!
I'm a little bit scared to screw my phone and be unable to restore it with iTunes.
What should I do ??
Any help will be appreciated !!
Thanks a lot
Frank

I'm dubious about this. It says it doesn't require SHSH files, but then asks you to restore 4.3.3 using TinyUmbrella with your hosts file commenting out saurik's server. Then it says you'll end up with a 1013. That would ONLY work if you had an SHSH on file for TinyUmbrella, or if you had your SHSH on saurik's server -- else you would just get 'The device is not eligible for the requested build'.

I find it easier to believe that the person who wrote this had their SHSH on file without knowing it than I believe they managed to find a way to work around the SHSH restriction. The steps just don't provide any actual solution to the problem, they're just asking you to restore to 4.3.3, then kick it out of recovery (which you can't do either without SHSH), then use iFaith to grab the partial 4.3.3 blobs. If you *could* restore down to 4.3.3 to the point at least that 4.3.3 was on the phone, you would have needed to have the SHSH...

I can't say for certain, as I do have my SHSH blobs, but it doesn't seem to me like this is a solution for not having your 4.3.3 SHSH at all. But, the steps they provided shouldn't cause any problems. I reviewed the hosts file and the other things they've provided, and though I don't think they'll cause any problems, I also don't believe that they'll work...

Quote:

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Originally Posted by n1ckn4m3

I'm dubious about this. It says it doesn't require SHSH files, but then asks you to restore 4.3.3 using TinyUmbrella with your hosts file commenting out saurik's server. Then it says you'll end up with a 1013. That would ONLY work if you had an SHSH on file for TinyUmbrella, or if you had your SHSH on saurik's server -- else you would just get 'The device is not eligible for the requested build'.

I find it easier to believe that the person who wrote this had their SHSH on file without knowing it than I believe they managed to find a way to work around the SHSH restriction. The steps just don't provide any actual solution to the problem, they're just asking you to restore to 4.3.3, then kick it out of recovery (which you can't do either without SHSH), then use iFaith to grab the partial 4.3.3 blobs. If you *could* restore down to 4.3.3 to the point at least that 4.3.3 was on the phone, you would have needed to have the SHSH...

I can't say for certain, as I do have my SHSH blobs, but it doesn't seem to me like this is a solution for not having your 4.3.3 SHSH at all. But, the steps they provided shouldn't cause any problems. I reviewed the hosts file and the other things they've provided, and though I don't think they'll cause any problems, I also don't believe that they'll work...

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I'm also skeptical, each time someone has posted a "downgrade without SHSH" guide - careful inspection of the guide reveals that it isn't actually true.

In this case, I think that the guide is taking advantage of the fact that the NOR firmware images are unchanged from 4.3.2 through to 4.3.5 (although the encryption/SHSH wrapper is unique to each iOS version).
So I think their approach is to create a hybrid/Frankenstein of jailbroken 4.3.3 with nor images properly signed for 4.3.5 and a pre-pwned OS. I can see how this could be "restored"
I'm unsure how this will work with the kernelcache, so I doubt that this could boot untethered.