Any cryptoanalysts here?

[loobian]

Hi!

I've been developing a crypting algorithm for sometime...
I am finally done...
The algorithm is symmetric. I am using a table, made from me.

So, anyone good here, willing to try this out? I can publish some simple text here + the table. You try to decode it. If you do- you beat me! If you don't- we'll see what we gonna do.

Thanks!

[Syntaxx]

Well, I'm definitely not a cryptoanalyst, but I'll give it a shot.

[Jimbo]

this could be a contest!!!

[RecursiveS]

OK Loobian - bring it on!!!

I'll have a go.....

[loobian]

Okay, I will need some time to implement it and write the code.
I will publish it here, later today or tomorrow.

We'll have great fun here!

[loobian]

By the way, I recommend to all of you, to read this article:

http://www.hermetic.ch/crypto/intro.htm

It's very good and informative... just to bring you into the subject before the real game starts!

P.S. I'd be very happy to work with you on breaking this code, even I will know the key... I will be interested in the approaches you guys will use...

I'm so eager to start...

[Justin]

Cryptanalysis is sexy. Bring it on.

[loobian]

Hi folks!

I had a math exam today, and I had a lot of work to do for it, that's why I didn't post the data earlier...
I will now write a program in C++ to implement my algorithm (which is pretty amateurs, but it's fun after all!), and when I am ready I will encrypt some text, and will publish it here + the table.
What else would you guys need to work on that? The key?! Sorry, the key is secret!

[Justin]

how about the plain text then

[loobian]

Hi folks!

Here it is, I am ready. I made a C++ program that implements my algorithm.

Here is the table:

Code: Select all

c/y9ojhavw5;ge72?klb06d3t@(^:
ng(5ytu^c02z?ord:fl9!x13pa/@;
z93ihacx0rp^eg6(vtsdmko21!@?/

Here is the header:

Code: Select all

a b c d e f g h i j k l m n o p q r s t u v w x y z <SPACE> . ,

Just to make it clear. The table and the header are connected, but the header is just for you to see which sign to which letter is. i.e. 1-26 signs are for the letters a-z (small letters only!). 27th sign is SPACE, 28th is dot, and 29th sign is comma.

Here is the chipertext:

Code: Select all

ahz^6(hxhtt9ri1(d^0s(0l@z(dysd(@c@x7(y@17m/o0;^/g6b@fhz9@9x0l@9h2b@/9hyz!sh(0t@17m/i6(@cd@ghngs(d^zd(ep@z;crt0bx?@ocs/9t7pyg@/1/160@/@s7@gzi(h^@@7pn1@dxnd@o^lh@lxrm^9@c@ok09h@ahfh@(@c@i0go6@(0/rmld/ozed/d6(xnkh(sreh(dy2d(0o@xoty@@l6/dxcd/160@um1l@(zg(ortp(6o@9khnp0ec/e1(zzc6k09xe(@rpzt@9xzb@cs@vd/@0(d^0g5@9x0l@cs@;6oc@ogrmca@96@dzfe@t6!t@/tn0gl@/31c@/(@l@/160@nth(h3(hydcgc(d^h@og5@6j@9xh(dy2d(dr@avgcsx(ocdx(ird@/m9@0b@10^;@o6d(@l6tk1/0@ce/g6b@9xzb@ldm205@1od/zd(^yzsb@p6m(s^6m;i/9h(xn((t@9xzb@9xh(^ygcad/6a(d^h@7m9(mb@t0^o@c@h(@9xh(3^0(ot9h2b@cs@bxy@scey@zl@9xh(^ygcbx/6a(d^h@vgdmd(ac^h(0/h@bxy@(;zcgdo29@@vg/dxo@oh2b@xhtv6o@@v@10^;@?zpo@g6da@zhghd^s@b6/9h(icaaotygd(3pz@hmps

Okay guys I am expecting your questions. Go break it!

[raimo]

Does the header mean that the plain text consists of the characters a-z, space, dot and comma?

Btw, if there's a secret key which is used to encrypt/decrypt the message then you can publish the C++ source of the algorithm, right? :)
Otherwise people couldn't trust on your algorithm if they didn't know what it is based on. :( Additionally, it would make decrypting the message and finding the secret key much easier for us! ;)

[loobian]

Hi raimo!

Does the header mean that the plain text consists of the characters a-z, space, dot and comma?

- Yes! Simple version is that...

Btw, if there's a secret key which is used to encrypt/decrypt the message then you can publish the C++ source of the algorithm, right?
Otherwise people couldn't trust on your algorithm if they didn't know what it is based on. Additionally, it would make decrypting the message and finding the secret key much easier for us!

The thing is that using bruteforce, and knowing the algorithm you can break it in a matter of hours with regular PC... for example, this text was crypted with 5bit key + one more value that you must know.
But if I give future information, then the algorithm will be known, and breaking this will go to using brute-force and nothing else...
This is plain boring!

What I was interested, was if anybody here can break this WITHOUT knowing the algorithm?

What do you guys think?

After all, I will publish the code here, but I wanted to see if anyone can break it without knowing the encryption algorithm.

[Wizard]

Curious now, how does the receiver of the message decrypt the code? What is your flow of message passing. Like, suppose I wanted to send you a message, and wanted that to be encrypted. Where would the encryption/decryption keys come from?

[loobian]

Hi Wizard!

The symmetric algorithms (also know as private-key-algorithms), are not usually used to transfer messages. Or even when you use them for that, the key is usually being given to the other party via a secure channel, or personally. For example, embassadors and politics, who receive encrypted messages with symmetric-algorithms (i.e. like this one), these people have the key delivered personally, usually in a briefcase which is carried by well guarded person.
There is another reason symmetric-algorithms are not usually used for messages: symmetric-algorithms, due to their 'nature', can encrypt much faster than asymmetric-algorithms (also known as public-key algorithsm...like PGP for example). Asymmetric algorithms encrypt a lot of slower, and they are mainly used to encrypt small amount of data. However symmetric algorithms encrypt a lot of faster, and they are more often used to encrypt big amount of data... backups or personal data or such...

I hope this answered your question...
If you still have any doubt- ask me.

Thanks!

[raimo]

So, is the text encrypted and decrypted using the same algorithm(and key)?