MIT OpenCourseWareThe Massachusetts Institute of Technology provides free online access to teaching materials for nearly all of its courses, allowing students and teachers to enjoy unrestricted access to these resources. General categories represented on the MIT OpenCourseWare website include mechanical engineering, mathematics, electrical engineering and computer science, economics, management and liberal arts.
Hashing in computer science: fifty years of slicing and dicing by 
Principles of computer security : CompTIA Security+ and beyond by 
