Do not use default options for the scrypt utility!
Here is example with more secure options:
$ sudo apt-get install scrypt $ scrypt enc -M 1073741824 -t 200 secret.txt encrypted.scrypt
If you have several GB of free memory you can increase the memory usage several times.
My tests confirm that the "-t" parameter is not working correctly - it takes less than 200 seconds to derive the key from your password.