R help - Feb 2014 - Running an encryption function on a column in a data.frame

I am trying to encrypt postcodes (zipcodes) which, in my datasets, are
strings with 8 characters, including spaces.  By referring to other help
files and other R resources I've built some (clumsy looking) code that turns
a postcode into an output I'm happy with.  See below.

library("PKI")
#make a character string of the post code in 8 character format
x<-"GG22 1WD"
#get it into a string of numbers
y<-raw2hex((charToRaw(x)),sep="")
#make a 16 digit pin for the key, in this case with a simple set of sequential
numbers
pin<-as.raw(1:16)
#make a encryption key
mykey<-AES(pin,mode="ECB")
#encrypt the postcode
z<-mykey$encrypt(y)
#finally convert this to a manageable string
pccrypt<-raw2hex(z,sep="")
#summary of the outputs
x
y
z
pccrypt

Now, I?ve got a couple of questions about this

Firstly and most importantly if I have a data.frame where one of my columns
contains these postcodes (e.g. df below) how can I run this workflow (or
something slicker, that does the same thing) and put the result into a
column in the data.frame? I?ve tried making a function and I?ve tried
some of the plyr commands, but been unable to do achieve this.

Secondly there seem to be a lot of steps to get the text string into a
format that the AES command can use, is there a way to make this simpler?

#make a simple data.frame with some sample codes
postcode<-c("AB5  2TG","B1   8AA","TG22 4XB")
df<-as.data.frame(postcode)
df

Any help gratefully received.

GavinR