"In recent months, we have identified a significant rise in the scope of cyber attacks by Iran which are carried out directly by Iran and its proxies Hezbollah and Hamas," he told a cyber security conference at Tel Aviv University, referring to the Lebanese Shiite militia and the Palestinian Islamist movement which rules Gaza.
"The targets are essential systems," he said without elaborating, in remarks communicated by his office.
"We are building the capability to deal with the attacks and we are holding back most of them while aspiring to build a 'digital Iron Dome'," he said of Israel's vaunted missile defence system.
In April, the Shin Bet domestic security agency reported what it said was a mass assault by hacker groups, although it caused only negligible damage.
In November, Israel said it was hit by an "unprecedented" cyber-warfare campaign as it waged an eight-day operation against Gaza militants.
At the time, the activist group Anonymous claimed it had downed or erased the databases of nearly 700 Israeli sites in protest against the offensive.