Girish Venkatachalam wrote: > --- David Irvine <[EMAIL PROTECTED]> wrote: > > --------------------------------- > Many thanks for a fantastic explanation and for > taking the time tohelp me. I was just reading some > docs there pointing me to this but youhave saved me a > good few hours. > > I will search out info for python info on PBKDF2 many > thanks for that.Just quickly though in point 3 does > that mean I should use ECB mode ornot if I am going to > split the file and send two parts to > differentlocations? > > Girish: > > You should avoid ECB mode at all costs. Always go for > CBC mode. ECB mode is just too easy to crack. > > I will try to give you an intuitive explanation of the > difference bet CBC and ECB. > > In ECB , each block of the file is encrypted > independently. So crackers can very easily correlate > cipher data and launch a chosen ciphertext attack or > some such. > > But in CBC mode, this is made very difficult by virtue > of the fact that each successive plaintext block is > not only encrypted with the secret key schedule, but > also X-ORed with the ciphertext of the previous block. > > > This ensures that the "diffusion" part of block > ciphering is really thorough. > > After all encryption is nothing but confusion and > diffusion... > > Feel free to ask whatever basic questions you have. > :-) > > Also don't get too hung up with IV. It is enough if > you are able to generate a secret key with good > entropy. > > All the best! > > regards, > Girish > > Many thanks this is all fantastic stuff. I appreciate your help and candour and what a well behaved list this is - serious pro's and not a sign of snobbery at all - great, I will live here for a while and learn and hopefully help others eventually.
David
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