A cipher (or 'product cipher') is something that iterates over several different operations such as substitution, transposition, modular addition/multiplication, linear transformation, etc, when encrypting plain text data into 'cipher' text.
When a cipher is 1024 bit, that means that there are 1024 bits that are used to determine how the plaintext will get encrypted (1024 bits => 128 bytes). Currently, the US government standard for product ciphers is 128 bits => 16 bytes (they say it is secure enough...and it probably is for awhile). As we are the Empire, we require something a little more secure.
I won't get into the math that shows how many different combinations can result from different cipher strengths, but the cipher we're using will pretty much make any plaintext look like a randomized bunch of characters.
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Grand Moff Kadann, Dark Lord
Head of the Vast Empire High Council
HHC/GM Kadann/HC-1/mSSD Atrus {EE}{MoH}{TT}{SY4}