Quote Originally Posted by jacek View Post
Because you use a block cipher which can encrypt only whole blocks.


Still AES will be the strongest part of your encryption scheme. And AES is as strong as the password, which should remain secret.
So mean to say I shouldnt disclose my algorithm too... But if the hacker is really good like you( Jacek ) he can try all the combinations to guess what algorithm I have used. Isnt that possible???

Again since I have written a program to encrypt and decrypt the files using blocks, will it matter?? as the hacker wont be aware of the program I have written. And he needs to first design the program and logic I have used to encrypt and decrypt.

Sure but, again, he will need some knowledge of C++, crypto++ and all the tools needed (i.e. compiler toolchain, library installed, ...) so this is probably not the right way to go...
What if he is an expert in some scripting language like perl or ruby. It can also be Java, but doesnt know C++...
Suppose I just encrypted the file ( AES::CBC ) and send it. My friend receives the encrypted file and he knows my 'passpharse' but he doesnt know what program, what language etc. But he guessed it is in AES::CBC. Now he writes a perl program ( his own ) to decrypt the file with same passpharse. Is he going to succeed? Can he decrypt the file? This case happened to me and my friend says ' FILE IS NOT DECRYPTING '. So what should I say the file was encrypted perfectly and is safe.