0
$\begingroup$

Asymmetric encryption schemes do leak something about the encrypted plaintext: the length of the plaintext. How can this be mitigated?

My solution: Padding the plaintext with some string of the arbitrary length – add 1 and then a string of zeros

What are some other ways this information leak can be mitigated?

$\endgroup$
  • $\begingroup$ compression of plaintext? $\endgroup$ – Richie Frame Feb 5 at 1:48
  • 3
    $\begingroup$ Some information is always leaked. Take a ciphertext of X bytes, then the plaintext is not an uncompressible byte array of a larger size. Q.E.D. If you have generic RSA encryption then the ciphertext size doesn't show any info on the size of the plaintext other than that the plaintext is ciphertext - minimum padding overhead - or smaller. Unless side channels leak this info of course. $\endgroup$ – Maarten Bodewes Feb 5 at 2:25
  • $\begingroup$ Does having the RSA message be a key to encrypt the real payload work for you? $\endgroup$ – forest Feb 6 at 4:18

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Browse other questions tagged or ask your own question.