By default, TiddlyWiki's WebServer serves resources over the insecure HTTP protocol. The risk is minimal if it is only being used within a private, trusted network but in many situations it is desirable to use a secure HTTPS connection.
Certificates can be obtained from a certification authority such as https://letsencrypt.org/, or you can create a self-signed certificate for internal testing.
To create the required certificate files with the popular openssl utility:
openssl req -newkey rsa:2048 -new -nodes -keyout mywikifolder/key.pem -out mywikifolder/csr.pem openssl x509 -req -days 365 -in mywikifolder/csr.pem -signkey mywikifolder/key.pem -out mywikifolder/server.crt tiddlywiki mywikifolder --listen username=joe password=bloggs tls-key=key.pem tls-cert=server.crt