#1
  1. No Profile Picture
    Registered User
    Devshed Newbie (0 - 499 posts)

    Join Date
    Dec 2011
    Posts
    5
    Rep Power
    0

    Encrypted file is bigger


    Greetings,

    i've got a question regarding RSA Encryption Algorithm...

    my friend wrote for me a small application which encrypts/decrypts files with RSA...

    5 mb file which is encrypted with 2048 bit key is about 25 mb in size...

    why it is increasing so much after encryption process???
  2. #2
  3. No Profile Picture
    Lost in code
    Devshed Supreme Being (6500+ posts)

    Join Date
    Dec 2004
    Posts
    8,317
    Rep Power
    7170
    I recommend using TrueCrypt instead. The majority of weaknesses in encryption are caused by implementation mistakes, and it doesn't sound like your encryption program is implemented correctly.
    PHP FAQ

    Originally Posted by Spad
    Ah USB, the only rectangular connector where you have to make 3 attempts before you get it the right way around
  4. #3
  5. No Profile Picture
    Registered User
    Devshed Newbie (0 - 499 posts)

    Join Date
    Dec 2011
    Posts
    5
    Rep Power
    0
    Originally Posted by E-Oreo
    I recommend using TrueCrypt instead. The majority of weaknesses in encryption are caused by implementation mistakes, and it doesn't sound like your encryption program is implemented correctly.
    you mean that it is cause by the mistake in source code?
  6. #4
  7. No Profile Picture
    Lost in code
    Devshed Supreme Being (6500+ posts)

    Join Date
    Dec 2004
    Posts
    8,317
    Rep Power
    7170
    There is no way I can tell that based on the information you've provided.
    PHP FAQ

    Originally Posted by Spad
    Ah USB, the only rectangular connector where you have to make 3 attempts before you get it the right way around
  8. #5
  9. No Profile Picture
    Registered User
    Devshed Newbie (0 - 499 posts)

    Join Date
    Dec 2011
    Posts
    5
    Rep Power
    0
    Originally Posted by E-Oreo
    There is no way I can tell that based on the information you've provided.
    Ok, for further investigation, i can deliver a source code in PM.
  10. #6
  11. No Profile Picture
    Lost in code
    Devshed Supreme Being (6500+ posts)

    Join Date
    Dec 2004
    Posts
    8,317
    Rep Power
    7170
    Ok, for further investigation, i can deliver a source code in PM.
    To be perfectly straightforward, I'm not going to check the source code to see whether it is correct, sorry. It would simply take me too long to do that. It has been several years since I last implemented the RSA algorithm, and I probably am not familiar with the programming language in which the code is written.

    If your friend is not skilled enough to tell you whether the code is correct or not, then you shouldn't trust them to write an encryption program. If you don't trust your friend to tell you whether it is correct or not, then you shouldn't trust them to write an encryption program.

    There are very few good reasons to make your own implementation of RSA. All major programming languages have standard, trusted libraries that can perform RSA encryption correctly and securely. Ask your friend to use those instead of implementing their own.

    My observations about the correctness of your friends program is based solely on my experience with TrueCrypt. In TrueCrypt, I can create a 10MB container volume and put 9.74MB of data into it. So there is some overhead, but it's not very significant.
    PHP FAQ

    Originally Posted by Spad
    Ah USB, the only rectangular connector where you have to make 3 attempts before you get it the right way around

IMN logo majestic logo threadwatch logo seochat tools logo