iOS Programming

I wrote the app for last year's RBS 6 Nations rugby tournament and I'm almost at beta for another app.

Wish I had the spare time to develop some of my own ideas though. :(
 
Tunney, what is your new app going to be based around? Any shots?

I'm busy writing some changes to my app for V1.1 submishing if my V1.0 gets approved. It will have an iAd banner for the iAd Network and busy adding a map view with pin drops of the location.
 
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Check out the Geeky Lemon tutorials on YouTube, they are really basic but perfect if you know next to nothing about Xcode/Objective-C.
 
They don't work properly some of them in xCode 4.3, unsure why but following his tuts don't work some of them.

EDIT: The sample files work fine it's just the code that doesn't, while watching and doing the tuts.
 
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They don't work properly some of them in xCode 4.3, unsure why but following his tuts don't work some of them.

EDIT: The sample files work fine it's just the code that doesn't, while watching and doing the tuts.

They probably don't work due to ARC. Quite easy to work around/fix
 
I've been working on my latest app, an Enigma Machine simulator that lets you sms the encrypted text. Works well but I think I'll add on a whole heap of info regarding its history and how it works. The encryption routine was particularly interesting as I was wanting to emulate the physical rotors and reflector found in the real device. One of those things that's simple once done but tricky to get your head round when doing.
 
They probably don't work due to ARC. Quite easy to work around/fix

The problem is though a lot of online guides are like this. They don't work due to changes in code that Apple have implimented.

Was thinking about having a play around but Xcode is mac only! :(

This is a good thing.

Sorry, only just seen this.

I'm using the Xcode 4.5 developer preview.

Nice, I stuck with the 4.3.3 version until it comes out officially. I did have a play around with it but I shall wait.
 
4.5 is far far far more stable than 4.3.3, just can't submit with it.

As you can run the two side by side so it makes sense to use 4.5, then if you need to submit compile with 4.3.3!
 
I've been working on my latest app, an Enigma Machine simulator that lets you sms the encrypted text. Works well but I think I'll add on a whole heap of info regarding its history and how it works. The encryption routine was particularly interesting as I was wanting to emulate the physical rotors and reflector found in the real device. One of those things that's simple once done but tricky to get your head round when doing.

I'd love to know how that worked. Never could get my head around the Enigma in the books.
 
The Enigma machine is quite simple in the mechanical sense, in that it alters the path of a circuit so that when A is pressed a light X lights up and so on. A series of rotating disks (the scrambler), alters this circuit every time a key is pressed, so pressing AAAA would produce for instance XTSB, thus preventing frequency analysis of letters, the main tool of the day for cracking cyphers.

There is a bit more to it than that though, there's also a plug board for transposing some of the letters that go into the scrambler (rotating disks) and a reflector, which returns the signal back through the scrambler before turning on the appropriate light.

The important bit though is that for a given rotor and plugboard configuration, plain text in gives you encrypted text and for the same configuration, encrypted text in gives you plain text out.

The difficulty I had was reproducing this electromechanical behaviour in software. In the end I used arrays to mimic the rotors and reflector. It was easy getting the encryption happening but took a while to enable the decryption. In other words it transposing the plaintext but unable to derive the plaintext from the encrypted text, which was thus a waste of time. Finally cracked it though.

The main screen scrolls up to show the plug board.

There is some poetic licence with my version in that there is a space key and a key to SMS the encrypted text.

Still at an early stage but the guts of it are working.

Enigma1.jpg


Enigma2.jpg


Still lots to do.
 
That looks super. Its a nice coding project.

I think from my memory that the code breakers built in effect a virtual enigma machine from decoding the encrypted transmission.
 
They used devices called Bombe's, which were like a number of Enigma machines wired together. The Polish were able to decrypt the Enigma transmissions prior to WW2 but the Germans improved the encryption, so it was down to the people at Bletchley Park to crack it.
 
I seem to remember the Poles had an early copy of an actual machine. But didn't tell any one for a good many years. Only when they started having problems decoding it did they start cooperating with everyone else. That said its a massive story and its a while since I read it.
 
Yep it was something along those lines. For a good read on encryption including the Enigma machine and how Mary Queen of Scots was caught out among others, have a look at The Code Book: The Secret History of Codes and Code-breaking by Simon Singh. A very interesting books on a subject that can sometimes be a bit dry.
 
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