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THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE UNAUDITED FINANCIAL STATEMENTS OF NETWORK-1 SECURITY SOLUTIONS, INC. FOR THE PERIOD ENDED MARCH 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.

3-MOS DEC-31-1999 JAN-01-1999 MAR-31-1999 4,590,000 0 508,000 (171,000) 15,000 5,195,000 1,194,000 (544,000) 6,852,000 1,299,000 0 0 6,000 44,000 5,503,000 6,852,000 70,000 383,000 152,000 466,000 1,812,000 0 0 (1,830,000) 0 (1,830,000) 0 0 0 (1,830,000) (.42) (.42)