def encrypt(data, opts={})
      data = data.to_s
      enc = @key.public_encrypt(data)
      if opts[:binary]
        enc
      else
        Base64.encode64(enc)
      end
    end
def encrypt(data, opts={})
      data = data.to_s
      enc = @key.public_encrypt(data)
      if opts[:binary]
        enc
      else
        Base64.encode64(enc)
      end
    end
Expects a public key at the minumum

 @param [#to_s] key public or private
 @param [String] passphrase to key

 Encrypt data using the key

 @param [#to_s] data
 @param [Hash] opts
 @option opts [Boolean] :binary (false) encode the data in binary, not Base64