module HTTParty::ClassMethods

def ciphers(cipher_names)

end
ciphers "RC4-SHA"
include HTTParty
class Foo

http://www.openssl.org/docs/apps/ciphers.html#CIPHER_SUITE_NAMES
You also can specify a cipher suite here, listed here at openssl.org:
You can get a list of valid specific ciphers from OpenSSL::Cipher.ciphers.
Allows setting of SSL ciphers to use. This only works in Ruby 1.9+. 
def ciphers(cipher_names)
  default_options[:ciphers] = cipher_names
end