"This didn't work so well as we struggled to get IBM to understand, so the battle continued for a while.

"The guys we initially had in our security team had been difficult to deal with; but when we outsourced they were moved to an organization they did not want to work for so they went from an internal group that was difficult to work with to an external contract, which was impossible."

As a result, he said Westpac created a small, embryonic security team to assess, with IBM GSA, what was required at the bank.

Blackley said over the past three years the bank and IBM GSA have been able to get the mix right.

He said the relationship has worked and now has a good understanding of what is required from the Westpac security team which is basically policy, some technology and policy policing, with IBM GSA providing services.