I’ve heard AES256 is the best encryption system but how does it work.
I know how basic encryption work.
In: Technology
What kind of explanation are you looking for? This is pretty difficult to ELI5.
As a description of what happens with AES,
First, the message data is split into blocks of 128 bits (16 bytes) and the block is arranged in a 4 byte x 4 byte grid. Each block then goes through a repeated process which has the following steps:
* Substitution, where each byte of data is replaced with another byte from a lookup table.
* the each row of the grid is shifted by a different amount
* a matrix multiplication is performed on the grid to mix up the data between the columns
* data from the users key (which comes from the password) is mixed into the grid
This is repeated a bunch of times.
Each step is reversible, but overall very non-linear to make it difficult to perform analysis on the blocks before&after the rounds.
So this system is pretty good and there are no known non-academic weaknesses. Is it the “best”? I’m sure better systems can be made. Chacha20 is faster than AES and is considered very strong.
The big advantage of AES is that it has been in use for many years so it has been battle tested. You can be pretty confident that there are no easy exploits since none have been found in such a long amount of time.
Another thing to note is that quantum cryptography will half the security of an encryption scheme (in principle). So a 128-bit encryption scheme will become 64-bit. AES256 will reduce to a 128 strength scheme which is still very strong, so AES 256 can be considered suitable for a post quantum computer world
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