Dear Friends,
I've been working on an encryption algorithm and now I need someone who can help me.

Actually I don't want to reveal the algorithm but I will give him/her the original text file and
the encrypted one.

He/she should be interested in decryption and try to find
the method of encrypting.

I am keenly aware that this a hard work and formidable useless task and nobody wants to participate but I'm just testing my chance.Maybe I will find someone who is crazy about cracking codes.

regargs

Creating new ciphers is not a game. Cryptanalysis leads to fatal consequences when flaws aren't spotted in time. So there's good reasons people don't want to or can help. Your first step should be to publish details to enable cryptanalysts to review it. If you don't want to then the simple answer is: DO NOT ROLL YOUR OWN AND DO NOT USE IT.

2 members found this post helpful.

Dear unSpawn,

first of all let me thank you for your kind reply and advice.
Already I know that this is a very critical matter but in my opinion, from a hacker's point of view nothing is clear.
He/She just starts to listen and manipulate data and tries to extract the real data.
He/she is not sure about applied algorithm in various levels and has to surmise, try and error.
This is the way I want an expert hacker to apply for my algorithm.
I submit even the original file to help him finding weak points.

regards

One plaintext and cyphertext pair isn't going to tell you or anyone else anything. If you're serious about your algorithm you'll copyright it if you feel that way (or, at least, make some proof when you wrote it) then release the algorithm and the implementation since the implementation is just as important as the algorithm. Unless you do this you're just asking somebody to stroke your ego by saying they can't see a relationship between plaintext and cyphertext. The only way I can see somebody wanting to do that is if you offer a reward -- then some people might spend a little time messing around.
Edit: You should also note that if a known plaintext attack did work then your algorithm is pointless.

2 members found this post helpful.

Oh, and if you're serious about writing an encryption algorithm then this is considered required reading by many.

Dear 273,

I've already read lots of such books and articles and developed an algorithm.
Now, I want to figure out how strength it is.

regards

really? it's got 784 pages.
somehow i don't believe that you even read that one book from cover to cover.

why do so many people feel compelled to show off to the point of telling untruths?

If you have read it you will know that what you are asking is not working out the strength of your cypher at all never mind whether you're trying to to determine the strength of just the cypher or the cryptosystem as a whole.

Dear ondoho

did I say that I read that book during last 2 days ????????????
let us open our eyes and see better.

thank you so much

"figure out"?
You wrote it. What's to "figure out"?
Mutually Exclusive Statement Of the Year

is my opinion.
That's a corker.

And if crypto is "your thing" and you don't at least acknowledge one of the foremost
authors on the subject, is a bullshit alert.

Prepare for Criticism.
Hope you have thick skin.

1 members found this post helpful.

I feel that, since the hint hasn't been taken, I ought t obe more explicit and link to this (sorry, on my Blackberry so can't format it better). https://www.schneier.com/essays/arch...y_the_imp.html
I'll also point out that both Rivest-Shamir-Adleman (or should that be Ellis-Cocks?) and the Diffie-Helman-Merkle key exchange are mathematically and real-world proven to be difficult enough to crack that it's not worth trying and that most symetric-key encypherment schemes short of a one time pad generally end up being cracked (for various values of cracked) on a regular basis not because their creators are bad at mathematics and computer science but due to their very nature.
I only type the above lest somebody else read this thread via Google and think that it would make sense for them to create their own encryption scheme. If you think you're up to writing and encryption scheme and you're not desperate to tell others exactly how it works so they can tell you how you messed up then you should give up now.

All of you have been of great help and now I see that the request is appropriately answered and the issue is totally solved.

thank a lot and regards

see you again

There are a few fundamentals of practical cryptography:

(1) You probably will never create an algorithm or a system better than one you can grab off the shelf:
"Civilian-grade encipherment" is recognized to be very important, even by the "spook" agencies. A great deal of effort is constantly being made to create strong algorithms, and trustworthy infrastructure surrounding those algorithms. These systems protect terabytes or petabytes of information every day.

(2) There is no "security through obscurity."
No one will pay the slightest bit of attention to any algorithm that its creator will not fully reveal. A fundamental of cryptography is that Eve knows everything about the entire system that Alice and Bob are using, except for one thing: "the key." Eve has a copy of the source code, and in fact it is "the correct source code."

(3) A "break" must be usefully and consistently exploitable, to be called a "break":
It's not good enough that Eve is able to brute-force a single message given sufficient aeons. (That's called a "theoretical break.") What Eve needs is a practical break: something that allows her to defeat the cryptographic protection easily enough, quickly enough, and consistently enough to be a serious threat.

(4) Forget "one-time pads!":
If you possessed the perfectly-secure means to share a one-time pad between Alice and Bob, why not use those means to simply share the message itself?

But also: it is impossible to detect that a one-time pad might have been somehow stolen. If Eve somehow did possess a copy of it, Eve could use it to forge messages or, if she could be a (wo)man in the middle, to tamper with the messages ... undetected and undetectable.

A practical cryptosystem must provide three protections:

1. That the message is concealed. (Of course ... although this step is actually optional! Maybe you only want to vouch for the message, and it is unnecessary to conceal it.)
2. That the message as-received is identical to the message as-sent.
3. That the message actually did come from its purported sender.

The many strong civilian systems that you can have in your hot little hands at no cost, all are able to do all of these things.