Key-Morphing
Game-changing new concept introduced by Vesper
Ever imagine how tedious it would be to change a crypto key from one to the other? You have to decrypt the entire cipher text, store it, generate a new key, encrypt again with the new key, and make sure to delete the old cipher text as well as the plain text used temporarily. Simple and straightforward, right?
Imagine that process happens by hundreds and thousands at the same time. Talk about the server load and the storage needed. The funny thing is, the plain text written during that time exists wide open, and that's when the hacking occurs. Hackers are smart; they know that encrypted data has no value for them.
Key-morphing solves this very problem by NOT doing any decryption process while changing the key and converting cipher text.
As shown above, encryption and decryption work like a circle of life for both the cipher text and plain text. Cipher text has to be decrypted to become a plain text, and plain text has to be encrypted to become cipher text.
Vesper, on the other hand, skips this procedure and jumps between two cipher texts.
Ever admired Mystique from X-Men? When she morphs into a different form, she never changes into her own self but morphs directly into the new form, and that's exactly how Vesper's key-morphing works.
Vesper treats and converts cipher text byte-by-byte as illustrated in the above picture. All calculation for the key-morphing occurs within the CPU as a meta data (not the plain text) form, and those calculation meta data never leaves CPU and is never stored/saved to the storage. Therefore, no decryption artifact remains in the system.
Now you may wonder how fast the key-morphing is. The speed is somewhere between encryption and decryption. As shown above, encryption rate for 570MB file is 171MB/s while decryption rate for the same file is 110MB/s, and the key-morphing rate is 153MB/s.
Key-morphing is about 10% slower than normal encryption; however, key-morphing is faster than performing both encryption and decryption. Of course, there is no decryption artifact, which means higher security as well as less load for the server and less storage space required.