apt-transport-https software package provides https download transport for APT, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install apt-transport-https
apt-transport-https is installed in your system.
Make ensure the apt-transport-https package were installed using the commands given below,
$ sudo dpkg-query -l | grep apt-transport-https *
You will get with apt-transport-https package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Administration Utilities |
| Package | apt-transport-https |
| Version | 1.0.1ubuntu2.13 [amd64, i386], |
| Description | https download transport for APT |
| Sub Section | Admin |