Question

In ransomware, an attack essentially leverages the main idea of hybrid encryption to attack users. Without paying Bitcoins to the attacker, a user cannot recover its data.

If an attacker can only leverage symmetric-key encryption to encrypt users’ data in a ransomware, then what are the major steps in this attack such that this attacker can still provide a copy of a decryption key if a user pays Bitcoins. From the perspective of this attacker, compared to using hybrid encryption, what are the limitations of this attack if it only uses symmetric-key encryption?

Answer 1

Solution:

• Since symmetric key encryption is susceptible to known plaintext or chosen plaintext attack, here the attacker will have a downside, since the encryption which his/her ransomware did is crackable and the user might be able to crack it and get the files without paying the bitcoins.
• The hybrid encryption, however, is hard to crack compared to the symmetric key encryption where the same key both for encryption as well as decryption.
• The symmetric key is also vulnerable to differential cryptanalysis and linear cryptanalysis.

I hope this helps if you find any problem. Please comment below. Don't forget to give a thumbs up if you liked it. :)