New Zealand businesses need to start divulging and sharing that they have been the victims of cyber crime as a first step to building national defences, according to the Institute of Directors.
A survey released earlier this week suggested cyber crime has cost New Zealand businesses more than $257 million in the past year.
But the Institute's chief executive Simon Arcus said there was no way of knowing the total cost, because companies were keeping silent about being victims, when they should be sharing the information.
"Cyber hackers are deciding that they can prey on individual companies, companies are reluctant to share and therefore the issues don't get well understood or collectively repelled."
If businesses were open to sharing information then the government should make the GCSB's expertise available, Mr Arcus said.