Kevin David Mitnick was born in Los Angeles on August 6, 1963 and attended James Monroe High School in Los Angeles He was a hacker, phreaker and social engineer, he was the most wanted in the world computer criminal in the 1990s, he was accused of numerous criminal activities of fraud and hacking in many major companies and the theft of their confidential data. The Federal Bureau of Investigation arrested Kevin Mitnick on February 15, 1995. He spent nearly five years in federal prison for the charges. He is now a cybersecurity consultant, author and ethical hacker, who founded a cybersecurity company called "Mitnick Security Consulting, LLC" and gets paid by companies for ethical hacking. He was first convicted at age 17, he and his two friends physically broke into Pacific Bell's COSMOS telephone center in Los Angeles in 1981 and stole passwords, including passwords to the door locks of Pacific's central offices Bell and some operating manuals for the COSMOS system. A gang member's girlfriend leaked the information to the police, soon Kevin and his friends were arrested and he was sent to the Los Angeles Juvenile Detention Center for three months, and was subjected to a year of probation supervised. In 1983 he was arrested again for hacking the Pentagon's ARPANET computer at the University of Southern California from a computer in the campus terminal room and was sent to prison for six months at the California Youth Authority's Karl Holton Training School, a juvenile prison. In 1987, he was accused of stealing software from the Santa Cruz Operation software company for which he was on probation for 36 months. Kevin's fourth arrest came in 1987 and 1988 for attacking Digital Equipment's Palo Alto research laboratory. paper ......er decrypts using his private key causing a lot of damage to everyone involved. This is why two types of signatures are used, non-exportable signature is used between friends or known people which is reliable to some extent but when before signing exportable signature on someone's public key you need to meet them first in person and exchange photographs and examine his public key and verify that it is his authentic key and confirm that everything is ok and then only you sign some public key with exportable signature otherwise it is a big risk to do so. This is the problem faced in pgp where anyone can enter a public key into the global server using someone else's name, which causes some difficulties for some people in identifying the right person if they do not follow the procedures and fall into the trap of hackers. This can be avoided by using signatures.