Update README.md

README.md

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 # horcrux
 
 Split your file into encrypted horcruxes so that you don't need to remember a passcode
+
+# How it works
+
+`horcrux` has two commands, `split` and `bind`.
+
+## Splitting
+
+If I have a file called `diary.txt` in my current directory I can call 
+```
+horcrux split diary.txt
+```
+and it will prompt me for how many horcruxes I want. If I want 5 horcruxes, it will encrypt my `diary.txt` file with 5 different secret keys, and then split the encrypted result into 5 equal parts to be stored in `.horcrux` files along with the 5 secret keys. This means that you will need all five horcruxes to put the thing back together again and decrypt it. The horcrux files will be created like so:
+```
+diary_1_of_5.horcrux
+diary_2_of_5.horcrux
+...
+```
+
+## Binding
+
+To bind the horcruxes back into the original file just call
+```
+horcrux bind
+```
+in the directory containing the horcruxes (or pass the directory as an argument).
+
+# Who this is for:
+* People who need to encrypt a big sensitive file like a diary and don't expect to remember any passwords years from now (but who paradoxically will be capable of remembering where they've hidden each horcrux)
+* People named Tom Riddle
+
+I have no idea if this program actually has practical use but it's a fun concept that I wanted to implement.