Since today, you can request Feed43 feeds over the secure connection. All you need is just use the following URL to request your feeds:
This, along with feed password-protection, will allow you to really secure your private feeds. We are likely to restrict this feature to paid feeds eventually, but currently you can use it with every feed.
Note that you can also use entire Feed43 site in secure mode (when creating or editing feeds, sending feedback to us, etc.). Just go to https://feed43.com instead of regular http://feed43.com address.
We are also planning to support https:// in feed source URL soon. Stay tuned.