+"""Enciphering and deciphering using the [Amsco cipher](http://ericbrandel.com/2016/10/09/the-amsco-cipher/).
+Also attempts to break messages that use an Amsco cipher.
+
+The Amsco cipher is a column transpositoin cipher. The plaintext is laid out,
+row by row, into columns. However, different numbers of letters are laid out
+in each cell, typically in a 1-2 pattern.
+
+It's clearer with an example. Consider we're using the keyword "perceptive",
+which turns into "perctiv". The text ""It is a truth universally
+acknowledged, that a single man in, possession of a good fortune, must be in
+want of a wife." is laid out in seven columns like this:
+
+ p e r c t i v
+ --------------------
+ i ti s at r ut h
+ un i ve r sa l ly
+ a ck n ow l ed g
+ ed t ha t as i ng
+ l em a ni n po s
+ se s si o no f ag
+ o od f or t un e
+ mu s tb e in w an
+ t of a wi f e
+
+The ciphertext is read out in columns, according to the order of the keyword.
+In this example, the "c" column is read first, then the "e" column, and so on.
+That gives the ciphertext of "atrowtnioorewi tiicktemsodsof utledipofunwe
+iunaedlseomut svenhaasiftba rsalasnnotinf hlygngsagean".
+"""
+