On Fri, Mar 19, 2010 at 12:35 PM, Barry Rowlingson
<b.rowling...@lancaster.ac.uk> wrote:
> On Fri, Mar 19, 2010 at 5:10 PM, Barry Rowlingson
> <b.rowling...@lancaster.ac.uk> wrote:
>> On Fri, Mar 19, 2010 at 5:00 PM, Hadley Wickham <had...@rice.edu> wrote:
>>> Hi all,
>>>
>>> Does any one know of any encryption/decryption algorithms in R? I'm
>>> not looking for anything robust - I want some way of printing output
>>> to the screen that the user can't read immediately, but can decrypt a
>>> little later. The main thing I don't want to the user to see is a
>>> number, so (e.g.) ROT13 isn't appropriate.
>>
>> You could just include the numbers in a ROT13-sort of algorithm. It
>> would end up being ROT-18 I guess...
>
> "ROT-18" (?) using chartr:
>
> > oldletters=c(letters,0:9)
> > old=paste(oldletters,collapse="")
> > new=paste(c(oldletters[19:36],oldletters[1:18]),collapse="")
> > chartr(old,new,message)
> [1] "g6c zsdw e65 kl.qr v633s9a"
> > chartr(old,new,chartr(old,new,message))
> [1] "you have won 23.89 dollars"
Thanks all for the suggestions. I ended up going with:
.old <- c(LETTERS, letters, 0:9, " ")
.new <- sample(.old)
.old_string <- paste(.old, collapse = "")
.new_string <- paste(.new, collapse = "")
encrypt <- function(message) {
chartr(.old_string, .new_string, message)
}
decrypt <- function(message) {
chartr(.new_string, .old_string, message)
}
Hadley
--
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/
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