According to experts, the operation avoided Israeli intelligence services by using "analogue tactics" in a time of digital war.
Following Hamas' devastating attack on 7 October, a source close to Hamas said: "Hamas used an unprecedented intelligence tactic to mislead Israel over the last few months, by giving a public impression that it was not willing to go into a fight or confrontation with Israel while preparing for this massive operation."
In one of the most striking elements of the preparations, Hamas constructed a mock Israeli settlement in Gaza where they practiced a military landing and trained to storm the compound.
The operation was divided into four parts, the Hamas source said, describing the various elements.
The first move was a barrage of 3,000 rockets fired from Gaza that coincided with incursions by fighters who flew hang gliders over the border. Israel has previously said 2,500 rockets were fired at first.
Once the fighters on hang-gliders were on the ground, they secured the terrain to allow an elite commando unit to storm the fortified electronic and cement wall that divides Gaza from the settlements and which was built by Israel to prevent infiltration.
The fighters used explosives to breach the barriers and then drove across on motorbikes. Bulldozers widened the gaps and more fighters entered in four-wheel drives, according to the scene described by witnesses.
A commando unit attacked the Israeli army's southern Gaza headquarters and jammed its communications, preventing personnel from calling commanders or each other, the source said.
The final part involved moving hostages to Gaza, mostly achieved early in the attack, the source close to Hamas said.
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