File Protector/Encryptor

[Koga73]

hello, im new to the forums if u didnt know, anyways, i made this pretty neat little program. Fairly simple, but very effective. basically, you select a file within it, then enter a password (up to 8 characters), and press the encrypt button. Itll encrypt the file using the password you typed in, makeing the file unusable (any file type). So, if it was a text file, and u used the lowest speed (for best encryption), it would be jibberish, and impossible to decrypt without knowing the password (since it uses the password for the actual encryptin method). To decrypt the file, do the exact same thing, itll decrypt it. If you enter the incorrect password, itll still decrypt it, but it wont do it correctly, so ull just have a fucked up file. And, the best part about it is, your file wont change a single bit in size!

Heres a screenshot, pretty basic:


Tell me whata think about the whole concept .

EDIT:
just realized, thats an older screenshot, i added in an area in the new version to set the encryption speed (the speed is just how many characters it jumps between each encrypted character, so with big files, the more jumps the faster it goes, but less secure, espically with text, a fast speed wont do much).

[iago]

How does the encryption work? Is it a standard encryption, or did you invent it yourself? 

Also, why limit passwords to 8 characters? Passwords should be _AT LEAST_ 8 characters, preferably more.  8 characters passwords are possible to bruteforce.

[Blaze]

I bet its something he made up.

[Koga73]

Well, idk, i just figured 8 characters would be fine. And as for bruteing it... its not possible to... if you put in the right or wrong password, itll still decrypt it, so unless you can make a program to go thro all the combos, and then check to see if the file has been decrypted correctly, bruting it wont work.

What it does is goes character by character (stepping by the speed, the speed can be from 1-1024, as long as the number between 1-1024 can be mod by the size of the file), and each character it comes to, goes thro each character in the password, converts that character into ascii, and converts the character in the file into ascii, then Xors the ascii from the character in the file by the ascii in the character of the code. So, if u use an 8 character code, itll Xor each character in the file 8 times. So, when u decrypt it, it does the exact same thing.

Incase you dont know what Xor is, ill explain it real quik.

12 xor 6 = 10
how?

00001100 = 12 in binary
00000110 = 6 in binary

so, match coorsponding columns, and if the numbers are the same, then the resultant = 0, if not, the resultant = 1, so the end result would be:

00001010, or 10 in binary.

[Blaze]

unless you can make a program to go thro all the combos, and then check to see if the file has been decrypted correctly, bruting it wont work.

Well, why would you do it any other way?

[Koga73]

err... i know how bruting works... but when its encrypted, and if its an exe lets say, itll be corrupt/nonworking until decrypted (usable again). So... if u were to go thro every combo, and try to decrypt it, it would decrypt it no matter what you typed in, but you wouldnt get a working version until u got the right pass typed in. And since u decrypt it each time, it would keep decrypting the decrypted file. YOud have to check the file to see if it works like its supposed to (which idk how ud even go about this), and if not, reencrypt the file, the goto the next combo.

[Blaze]

Send me the encryptor, and an encrypted version of it.

[iago]

I'd make a copy of the file, decrypt it with a password, check if it's a valid exe (by checking if the first 2 bytes are MZ, or using the 'file' command on Linux).  If that doesn't work, move onto the next one.  That can be automated and done quite quickly, especially considering I only have to decrypt the first 2 bytes of the file.

You should use AES or DESx3. 

[Sidoh]

http://sidoh.dark-wire.net/?fuseaction=tutorials.view&id=4

[Koga73]

hmm, ok, ill find a place to post it. Ill post a zip/rar file including the installer/program (a little shitty isntallr is included incase they dont got runtime files), along with an encrypted exe, lets see if anybody can get the exe working . Gimme a day or so to post it, ill reply with a link.

[iago]

When will a Linux version be available?

[Sidoh]

Yeah.  Bruting 8 bites is a pretty insignificant task.

[Quik]

Yeah. Bruting 8 bites is a pretty insignificant task.

It takes me 8 bites to eat a piece of pizza. Maybe you're thinking of something else? :p

[Sidoh]

Yeah. Bruting 8 bites is a pretty insignificant task.

It takes me 8 bites to eat a piece of pizza. Maybe you're thinking of something else? :p

Fast typing FTW.

[Blaze]

It takes me 8 bites to eat a piece of pizza.

8?  I must be doing something wrong...

[iago]

Yeah.  Bruting 8 bites is a pretty insignificant task.

Do you mean bits or bytes? It's hard to tell

[Quik]

Yeah. Bruting 8 bites is a pretty insignificant task.

Do you mean bits or bytes? It's hard to tell

See my post.

Also: (16:25:34) Quik: There's a bit, and a byte, but bites are new to me

[iago]

Yeah. Bruting 8 bites is a pretty insignificant task.

Do you mean bits or bytes? It's hard to tell

See my post.

Also: (16:25:34) Quik: There's a bit, and a byte, but bites are new to me

The question still wasn't answered. 

[Koga73]

Ok, i made a simple exe in qbasic that contains a single word. Then, i encrypted the program with my program. So, lets see some bruting! If you crack it and get the answer.exe to work, just reply with the word in the program. Heres a url to downlad the answer.exe and the encryptor:

http://mercury.walagata.com/w/koga73/Crack_Me.zip

[Quik]

Ok, i made a simple exe in qbasic that contains a single word. Then, i encrypted the program with my program. So, lets see some bruting! If you crack it and get the answer.exe to work, just reply with the word in the program. Heres a url to downlad the answer.exe and the encryptor:

http://mercury.walagata.com/w/koga73/Crack_Me.zip

Oh, if only zorm visited these forums.

[Koga73]

hmm, well even if u dont crack it, could u at least respond sayin u tried?

[iago]

Sorry it took me so long.  The word is "Deliquesce".  The encryption key was "102", and the speed was "2". 

I can't believe how slllooooow your program is.  I write an implementation in C that encrypts your 16kb file, at speed 1, in milliseconds. :-P

[Joe]

wrote*?

Sidoh, thanks man! Much better than my old integral division encoding.

EDIT -
Heres my code. By no means secure, due to having the key right in it, but you go right ahead and do what you think is best with it. =)

Code: [Select]

Option Explicit

Public Function Decode(S As String) As String
    Dim Ret As String, Key As Byte, Char As Byte, I As Byte
    Key = Asc(Mid(S, 1, 1))
    For I = 2 To Len(S)
        Char = Asc(Mid(S, I, 1))
        Char = Char Xor Key
        Ret = Ret & Chr(Char)
    Next I
    Decode = Ret
End Function

Public Function Encode(S As String) As String
    Dim Ret As String, Key As Byte, Char As Byte, I As Byte
    Randomize: Key = Int(Rnd * &HFF) + 1
    Ret = Chr(Key)
    For I = 1 To Len(S)
        Char = Asc(Mid(S, I, 1))
        Char = Char Xor Key
        Ret = Ret & Chr(Char)
    Next I
    Encode = Ret
End Function

[Sidoh]

wrote*?

Sidoh, thanks man! Much better than my old integral division encoding.

Haha, sure.

Sorry it took me so long. The word is "Deliquesce". The encryption key was "102", and the speed was "2".

I can't believe how slllooooow your program is. I write an implementation in C that encrypts your 16kb file, at speed 1, in milliseconds. :-P

Lmao

[iago]

hmm, well even if u dont crack it, could u at least respond sayin u tried?

Well, are you going to admit that I rock or what?

[Joe]

iago rocks. (Please approve me. =p)