Computer geeks planning to attend the world's largest annual hacking party in Las Vegas next week will have a rare chance to talk to the head of the US National Security Agency – the first such high-ranking official to attend ever.

­General Keith Alexander, the NSA director who is also in charge of the US Cyber Command, will speak at the Defcon conference, marking the highest-level visit to date by a US government official to sucha gathering.

"We're going to show him the conference. He wants to wander around," Reuters quotes Jeff Moss, a hacker who organized the first Defcon conference 20 years ago, as saying.

Moss now sits on an advisory committee to the Department of Homeland Security.

Still, Moss said he expects there could be some controversy over Alexander's presence among the diverse hacker crowd that attends the conference.