There are many techniques to prove your worth to your organisation - and in these circumstances, email is your best friend.

(1) If the IT system contains confidential in formation and you have been ordered to ignore protocol to get him access - simply write an email to the big boss to that effect.

"Dear xx ,

I refer to our conversation earlier this morning, and note that you have asked me to by-pass protocol in order to grant xxx access to the confidential information on our company's IT system.

Please find enclosed herein the confirmation printscreen. xx now has access to the all confidential information on the company's system.

Cheers,
xxx"

Your job is not to make management decisions - simply to protect yourself in case of blow back. In a culture like this, DOCUMENT EVERYTHING.

(2) Your colleague jumping in to answer work on your behalf, this is even simpler. Reply all, including the asshole trying to steal your limelight, with additional information in order to value-add to his answer. The point of this email is not to be nasty, but to show that you have IN-DEPTH understanding of the project.... and not your asshole colleague.

"Dear xx,

Further to xxx's email, it is also important to note that xxxxxx.

Aside to xx,

Thanks for jumping on board so quickly, especially since you're not directly involved in the project. Much Appreciated!"

You should aim to positively respond to these negative matters and to value-add to your organisation. You cannot value add by being negative. You do not want to create trouble, you want to provide solutions.

As such, i agree with the poster above that refusing the asshole access to the IT system when directly ordered to do so is creating trouble. You are not the keeper of the confidential information - the Company is. You cannot take such decisions or instructions personally. In fact, you cannot take such organisational matters personally, which i feel you have done in this instance.