Power
If you're imagining becoming a rogue coder surrounded by piles of pizza boxes and Diet Coke, staying up all night to decode secret CIA messages, you can pretty much forget about it. As a cryptographer, you're the rule-abiding cog in a huge bureaucratic machine. You'll likely end up at a local law enforcement agency, a sprawling tech company, a university, or a research institute.
Unless, of course, your name is Marian Rejewski and you took down the Nazi German military Enigma cipher machine...in which case you've got a little power.
But in general, think of yourself as everyone's nerdy, number-crunching sidekick.