Security sources estimate that Hamas leaders Mohammed Deif and Yahya Sinwar were aware of the close surveillance by the Israeli intelligence community and used covert methods to communicate messages.

"No one understood this, not Aman (Military Intelligence), not the Shin Bet, nor the Mossad," admitted a security official. "Otherwise, they wouldn't have left the border unguarded, with no basic response from the ground or air."

Deif and Sinwar, under surveillance by Israeli intelligence, operated to convey messages covertly, security sources believe. According to assessments, Hamas conducted a meticulous preparation for an incursion on October 7, described by a senior security system official as "a perfect deception exercise."

An Israeli security official explained the tactics used by the Hamas military commanders for message transmission. "It's likely that the confidential details, instructions, and overall sentiment were reserved for face-to-face conversations or other means," he admitted. "In retrospect, the intelligence community didn't grasp this. Not the Intelligence Corps, not the Shin Bet, nor the Mossad. No one took it into account; otherwise, an alternative system would have been prepared in anticipation of a sudden escalation with the Gaza Strip. Otherwise, they wouldn't have left the border unguarded at the last stage of the holidays, with no basic response from the ground or air."

Hamas decoded IDF methods

According to reports, in the 2018 "Tropical Fruit" operation, IDF teams installed tapping devices in Hamas strongholds. The terror organization uncovered the attributed force in Khan Yunis. Some infrastructures remained in the area and were bombed, but others survived and fell into Hamas' hands, and likely with Iranian assistance, they managed to decode IDF methods.
Prime Minister Benjamin Netanyahu, flanked by Defense Minister Yoav Gallant (left) and IDF Chief of Staff Lt.-Gen. Herzi Halevi, holds a security assessment in Tel Aviv. (credit: HAIM ZACH/GPO)
Prime Minister Benjamin Netanyahu, flanked by Defense Minister Yoav Gallant (left) and IDF Chief of Staff Lt.-Gen. Herzi Halevi, holds a security assessment in Tel Aviv. (credit: HAIM ZACH/GPO)
"The operation's failure blinded the IDF in many respects," said a security official. "It set us back in terms of initiative and understanding of the bigger picture." In hindsight, the failure appears to have been strategic. While the IDF thought they had a clear picture, they saw almost nothing but weak signals that they struggled to connect."