updated the readme

README.md

@@ -1,2 +1,113 @@
-# psyfer
+psyfer
+ 
+# Overview
 
+Psyfer is a app which lets you perform various different ciphers to input 
+strings.  It also provides the ability to guess certain ciphers. 
+
+Psyfer is project for UC Davis ECS 235A Computer and Information Security
+
+# Getting Started
+
+If you have a working Go enviroment on your computer, you can download pull 
+down this repo and build this code.  Otherwise, visit https://derek.mcquay.me/ecs235a/ 
+for downloadsTODO
+
+Once you have psyfer, you can run commands like:
+
+    > psyfer vig -k xyz "this is my string"
+
+which will perform the vigenere cipher with a key of "xyz" on the given input
+
+# Concept
+
+Psyfer is built on a structure of commands, arguments & flags.
+
+**Commands** represent actions, **Args** are things and **Flags** are modifiers for those actions.
+
+# Usage
+
+## psyfer trans
+
+Running `psyfer trans [mode] [flags] [input]` will perform various different 
+transposition ciphers to your input string.  the possible options are `random`, 
+`railfence` and `split`.
+
+Here is an example:
+
+```
+psyfer trans railfence "my input string"
+```
+
+Likewise, you can also decrypt by adding the `-d` flag:
+
+```
+psyfer trans railfence "m nu tigyiptsrn" -d
+```
+
+## psyfer sub
+Running `psyfer sub [flags] [input]` will perform a substitution cipher according
+to a key file.  An example key file is found in the repo called key.json.
+
+Here is an example:
+
+```
+psyfer sub -k key.json "my input string"
+```
+
+Likewise, you can also decrypt by adding the `-d` flag:
+
+```
+psyfer sub -k key.json "ax nmpir krqnmb" -d
+```
+
+## psyfer vig
+
+Running `psyfer vig [flags] [input]` will perform the vigenere cipher with 
+the provided key.  
+
+Here is an example:
+
+```
+psyfer vig -k mykey "my input string"
+```
+
+Likewise, you can also decrypt by adding the `-d` flag:
+
+```
+psyfer vig -k mykey "decrypt this string" -d
+```
+
+## psyfer aes
+
+Running `psyfer aes [flags] [input]` will perform the AES cipher with keysizes 
+128, 192 or 256 bit in Electronic Codebook (ECB). The key is "baked" into the
+program (example keys found in FIPS publication 197.
+
+The default behavior is to return the hex representation of the string. the
+`-a` flag will display in ascii.
+
+Here is an example:
+
+```
+psyfer aes -k 128 "my input string"
+```
+
+Likewise, you can also decrypt by adding the `-d` flag:
+
+```
+psyfer aes -k 128 "my input string" -d
+```
+
+## psyfer guess
+
+Running `psyfer guess [flags] [input]` will return the top five most likely
+solutions to the caesar cipher provided.
+
+Here is an example:
+
+```
+psyfer guess "wklv lv d vhfuhw phvvdjh"
+``` 
+
+which will return "THISISASECRETMESSAGE" as the most likely answer