Name is just an ordinary name. I usually lok at the credits at the end of a film for names. Aliases/nicknames can be any word and should only be one word, not too long. Does not have to be decker/computer related. Your/the characters favorite candy/animal/thing works.
Giraffe, Otter, Hershey, Fork, Bandit, Sheriff
For computer related, come up with some "computer or math" words and use as is or do something with them.
D15quette, CĪre, Sleazer, Data, Giffer, Atar1, Vect0r,
or some variant on famous scientist/computer person.
Einstein, Zucker, Babbage, Woz,