Here is what I see at the prompt when I try to import the module

$ ghci
GHCi, version 7.4.1: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Prelude> :m +Crypto

<no location info>:
    Could not find module `Crypto'
    It is not a module in the current program, or in any known package.
Prelude> :m +Crypto.Hash

<no location info>:
    Could not find module `Crypto.Hash'
    It is not a module in the current program, or in any known package.
Prelude> :m +Crypto.Hash.Data

<no location info>:
    Could not find module `Crypto.Data'
    It is not a module in the current program, or in any known package.