The basic skills needed for invention are:

CPU Management II*
Power Grid Management II*
Electronics Upgrades III
Science III*
Hacking II
There are four racial encryption method skills. Each Tech II item requires a specific one of these encryption methods:

Amarr Encryption Methods
Caldari Encryption Methods
Gallente Encryption Methods
Minmatar Encryption Methods

Each invented item also has two advanced science skills associated with it. The advanced science skills are:

(Racial) Starship Engineering - one for the four racial factions (Amarr, Gallente, Caldari, Minmatar)
Electromagnetic Physics
Electronic Engineering
Graviton Physics
High Energy Physics
Hydromagnetic Physics
Laser Physics
Mechanical Engineering
Molecular Engineering
Nanite Engineering
Nuclear Physics
Plasma Physics
Quantum Physics
Rocket Science