[Newbie] how to crack this?

Hi,
I want to find out /how/ this is encrypted and how to decrypt it.
My limited searches so far suggest phrases such as "Adaptive chosen plaintext attack" and "probabalistic encryption", but I don't know squat.

I have encrypted the string
"Hello there, can you see what I am doing yet?\n"
twice and got:

00000000 FE406B54 5E240A7D FE543E55 5E240A4D *.@kT^$.}* *.T>U^$.M*
00000010 616EBB96 B2649FC1 01B5FE7E A5547B4F *an...d..* *...~.T{O*
00000020 8F39A5B4 AF416639 53D3E299 41CFF496 *.9...Af9* *S...A...*
00000030 4A6A2EA7 67BE8A22 C00FF243 0452EFEC *Jj..g.."* *...C.R..*
00000040 14646D2C E3B57510 6F636F9F 75C9A0ED *.dm,..u.* *oco.u...*
00000050 EE6413BB 04DCBE71 F185AB89 AFF102A7 *.d.....q* *........*
00000060 C502E32B 427D0167 B1C08753 9B2148AC *...+B}.g* *...S.!H.*
00000070 CF841741 6EBB47ED DF1266A4 D27CB4B7 *...An.G.* *..f..|..*
00000080 31A3B870 254DE469 25A355C0 626441B9 *1..p%M.i* *%.U.bdA.*
00000090 07BE843D 382FEA16 27C1B2DF 697F54E9 *...=8/..* *'...i.T.*
000000A0 20FDC5 DC165A * .. * *..Z *
<eof>

NO other info will be needed to decrypt this; in my layman terms those #A4 bytes hold the data and key, just not the how-to. From personal knowledge, I would also say that decryption (once you know the exact algo) would be _very_ fast, implemented by one man (smart but not an expert in this field) between 1991 and 1993 (whilst working hard on other stuff) and is unlikely to have changed much since. Highly unlikely to be PGP-ish, I would guess xors and maybe a smidgen of 64-bit integer maths, jumping about a bit, is all.

My problem is that he's effectively dropped support for this and gone another way; he can have that ball, I would love to be able to pick the old one up and run with it. I have no intention of wrecking anything he has done.
And no, co-operation is not his middle name.

So where do I get started, assuming I don't have years to spend studying?
I would consider it a bonus if I learn a few tips on not repeating mistakes.
If you had to crack/duplicate this encryption/decryption, what would you do?

Regards,
Pete

 

And the point of this is?

 

Rhetorically speaking, mainly to learn something.
Technically speaking, the binary shown is program code, that /anyone/ can run.
It's a compatibility issue: if I can run this propriety-encrypted code then I can create a competing product, so it is a bit like Microsoft's .doc format. I want to break the monopoly.

So, any ideas on where I should start, what I should read next?

Regards,
Pete

 

www.rapideuphoria.com, version 2.4, this feature has been dropped from 2.5: specifically the ability to create a shrouded component which can be used in other programs. 2.5 will still run things created with 2.4, but will now only shroud entire programs - I have no real interest in pursuing that but components is a different matter.

The free public domain executables will decrypt and run the code. At the moment there is no real competition, I plan to release an alternative in the next few months. I have got a few demo programs running, some of which use over 12,000 lines of included component, mainly a windows gui lib.
It would be nice if I could run programs which use the odd encrypted component (such as Bernie Ryan's W/XMOTOR, the very popular EuWinGUI by Andrea Cini, and my own Print Preview) but are otherwise open source.

Regards,
Pete

 

No takers then.
Obviously no one on this list has the slightest clue and you are all a bunch of <whatever> spouting drivel. It saddens me to think there are forums like this where people believe they are getting expert advice when in fact no-one has any idea what they are talking about.

Even if you think what I am asking is wrong, no-one has had the slightest courtesy to tell me why. That is just plain rude and I pity anyone who trusts anything said by the "regular posters" here.

Bye

 

Yawn... now tell me, why should anyone spend a given amount of time trying to crack a given encryption scheme, for free, anyway? For your benefit? What's this, "try to find bugs in my program so that I can fix it and sell it"?

 

I did not ask you for that.

I asked where *I* should start.
Please read the first and last lines of my original post again.

 

Ok, I would start with Schneier's Applied Cryptography, and what's referred in this. But "assuming I don't have years to spend studying" is a little weird. Exactly, how *much* time? Weeks? I don't think you or anybody can have a crash course in cryptanalysis and learn that much in a few weeks (or even a few months, for that matter).

 

*You* could get a good start by learning some manners.

Then go to Wilders Encryption Forum and try your luck there.

Sorry we're not sprouting your preferred strain of drivel here (NOT).

Oh, BTW, welcome to Wilders.

 

Thank you! That was exactly the sort of link I was hoping for.

Weeks, I can probably manage, and maybe stretch to a few months

I'll study that and probably come back with a slightly more educated answer, hopefully sometime still labelled 2006.

Yes, my apologies. However rattling the cage did get me the first step I asked for

Regards,
Pete

 

Rattling the cage as you put it, is not required or excepted around here.

Blackspear.