The final of the fifth Global Security Challenge on 11 November will see mentorship programmes and funding of $300 000 (£190,871)go to the best security SME and $200 000 to the best start-up.
Global Security Challenge is an annual business competition for security innovators and researchers, with finalists chosen by security and technology experts in a rigorous selection process.
The cash prizes are funded by the US Department of Defense, but previous finalists have been able to raise additional capital and win new business though the competition.
The technologies competing for 1st prize and the attention of investors, include a defence against web attacks using virtualised browsers, a low-cost, biometric and cryptographic technology, an identification technology based on the unique movement of peoples' eyes, and a bag- or package-sniffing technology.
Often excellent companies fall by the wayside because they do not have access to funding and investors do not have the confidence to invest because the technology they offer is so specialised, said Richard Wilson, director of the Global Security Challenge.
"This competition solves that by getting experts to identify the world's most promising security SMEs and start-ups, then bringing them together to pitch their ideas to investors", he said.
Last year's SME prize went to UK firm Kromek, while the award for the most promising security startup went to Israeli firm Adaptive Imaging Technologies.
Kromek produces a range of detection systems and was commended for its threat liquid identification system and a unit for screening multiple containers.
This year's finalists include online security firm iWebGate, based in the UK and Australia, and semiconductor firm DecaWave from Ireland.