Wiktionary
keys to the kingdom
n. (context idiomatic English) A resource, usually information or knowledge, the possession of which gives the possessor access to power.
Wikipedia
Keys to the Kingdom
"Keys to the Kingdom" is a song by American rock band Linkin Park from their sixth studio album, The Hunting Party. It has entered the UK Rock chart at number 33, although it hasn't been released as a single. The song was written by the band and produced by co-lead vocalist Mike Shinoda and lead guitarist Brad Delson.
Usage examples of "keys to the kingdom".
When I open this door, I'm going to slip the keys to the kingdom right into your hand.