Protecting Flash Memory of a Fujitsu MCU

I had a requirement to protect flash memory of Fujitsu MB95F128JB MCU but I could not find any satisfactory hardware/software tool to protect it. Later, I conceived an idea to hack its .mhx file. After adding the following line before the last line of the .mhx file, it had been protected.

S104400001BA

Ref: http://en.wikipedia.org/wiki/SREC_%28file_format%29