options for safe transfer of data to a server - ?

[Curt Ford]

My client wants to have a routine that records when a user first installs the project, by incrementing an item in a text file on his server. We've got it working well with ftp but I'm wondering if  whether sending the ftp login & password over regular ftp is a security issue; some digging in the archives makes me think that sftp isn't an option yet. 

Would https:// be an option to write to a file on the server? Would that require that they have an SSL certificate?

Any ideas on a good way to handle this?

Curt