UK and Australia-based SME iWebGate and Ghanaian start-up mPedigree have won the fifth Global Security Challenge.
They were among 13 of the world's most promising security companies competing for funding in the final, held in London.
The Global Security Challenge is an annual business competition for security innovators and researchers.
Finalists pitched their security innovations to a panel of judges in front of investors, venture capitalists and representatives of government and industry.
The cash prizes are funded by the US Department of Defense (DoD), but previous finalists have raised additional capital though the competition.
iWebGate won the best security SME category and was awarded $300,000 and mentorship from the Carlyle Group for its online security product.
The product set ups a virtual, highly secure reception area between an organisation's trusted network and volatile public networks such as the internet.
It is a low-cost product aimed at enabling businesses to improve the overall security of trusted networks while keeping it simple to do business on the internet.
mPedigree won the best security start-up category and was awarded $200,000 and mentorship from Advent Venture Partners for its world-first system that enables consumers to verify the authenticity of their medicines using free text messages.
John Morgan of the DoD's Technology Support Working Group said that instead of putting money into specific areas of research, the Global Security Challenge invites companies to offer solutions to problems and funds the best ones, which is a very effective use of funding.
"In the past five years, we've identified some really promising technologies that we may not have otherwise come across, and which will be important in the ongoing struggle to keep people safe without limiting their freedom," he said.