Nearly two-thirds (64%) of  Americans have not made an online purchase because of security concerns, according to a new poll by the National Cyber Security Alliance (NCSA).

When asked to explain why they did not make that purchase, 60 percent said it was because they were not sure if the site was secure, 51.4 percent were worried about providing information requested, and 48.4 percent felt a website requested more information than was necessary for the transaction.

"The Internet is a fabulous, convenient resource for gift givers to get a jumpstart on their holiday shopping and bargain hunting, but people need to stay aware and alert about the risks," said NCSA Executive Director Michael Kaiser.

"If there is any doubt about the security or authenticity of a website, hold off making the purchase."

The poll found 69.3 percent of Americans research potential purchases on the Internet, 68 percent make purchases online, 62.4 percent make online payments, and 38 percent buy items from online auction sites.

Those researching potential purchases from their phones also grew to 16 percent, up from 9 percent in 2009. A recent study published by NCSA and Norton by Symantec found that 87 percent of Americans felt safer going online with their PCs than with their phones.

"Businesses should take note: online customers are looking to make purchases where they see signs that a website is secure, have a clear understanding of how information collected about them is going to be used, and only information necessary to the transaction is being collected," Kaiser added.

"Online shoppers are being smarter and safer online, and that’s good for everyone."