Freezing will give you the longest storage of seeds, but you do have to make sure that their moisture level is low enough or the seeds will expand and crack and be ruined. They can also store well(but not as long), without the worry of whether they are of low enough moisture level, in a mason jar tightly sealed in the fridge, and for even better storage in the fridge wrap them either on the inside of the jar or outside with a material that will help keep out light.
A way we have found of drying seeds for the home gardener to bring the moisture low enough, and keep high viability is using a food dehydrator, with very careful monitoring of temperature, as anything over 95°F will damage the seeds viability. We always keep at 85°F to be safe. Even placing on a window screen with a fan blowing on them until they are dry enough works.