Input device lock

A computer security device for selectively interrupting data transmitted from an input device to a computer along a cable having a first and second end, a power line and a line effectuating data transmission from the input device to the computer comprising:

• a) an enclosure affixed to and surrounding a portion of the cable between the first and second ends;
• b) a lock switch electrically connected to the line effectuating data transmission in the keyboard cable;
• the lock switch having a first state that disables the lie and a second state that enables the line;
• and
• c) a key insertable into and removable from the lock switch only if the lock switch is in the first state, the key allowing the lock switch to be switched between the first and second states when inserted into the lock switch;
• whereby data transmitted from the input device is interrupted when the lock switch is in the first state but is unaffected when the lock switch is in the second state, and the computer acknowledges that the input device is properly connected while the lock switch is in either state since the power line is uninterrupted.

A computer keyboard lock for switching a line effectuating data transmission of a computer keyboard cable comprising:

• a) a lock switch connected to the line effectuating data transmission of the keyboard cable, the lock switch having a key receiving portion enabling switching between an on position and an off position;
• b) a key received by and switching the lock switch between the on position and the off position, the key insertable into and removable from the key receiving portion only when in the off position;
• and
• c) a rigid enclosure surrounding a portion of the keyboard cable where the lock switch connects to the line carrying the data, the lock switch mounted to the enclosure such that the lock switch connection to the line effectuating data transmission is inside the enclosure and the key receiving portion is outside the enclosure;
• whereby a computer keyboard is unable to send or receive data but is still acknowledged by a computer as being connected when the key receiving portion is in the off position, no lines in the keyboard cable other than the line effectuating data transmission are affected, and the computer keyboard functions normally when the key is inserted into the key receiving portion and is switched to the on position.

A method for controlling access to a computer, the steps comprising:

• a) connecting a lock switch to a cable having a power line and a line effectuating data transmission, the cable coupling an input device to a computer, the lock switch being electrically connected to the line effectuating data transmission, the lock having an on position wherein data can be transmitted and an off position wherein data transmission is inhibited;
• b) inserting a key into the lock switch;
• c) switching the lock switch to the on position such that the computer keyboard functions normally and the key cannot be removed from the lock switch
• d) switching the lock switch to the off position;
• and
• e) removing the key from the lock switch in only the off position;
• whereby the computer receives data from the keyboard only when the key is in the lock switch and the lock switch is in the on position, and the key can be inserted into and removed from the lock switch only when the lock switch is in the off position.

A method for temporarily preventing unauthorized access to a computer through a keyboard coupled thereto by a cable having a power line and a line effectuating data transmission, comprising the steps of

• a) inserting a key into a lock switch wherein the lock switch is connected to the line effectuating data transmission of the keyboard cable such that data transmission through the line effectuating data transmission is inhibited when the lock switch is in the off position;
• b) switching the lock switch to an on position such that the keyboard functions normally and the key cannot be removed from the lock switch;
• c) switching the lock switch to the off position;
• and
• d) removing the key from the lock switch in only the off position;
• whereby the keyboard transmits data only when the key is in the lock switch and the lock switch is in the on position, and the key is insertable into and removable from the lock switch only when the lock switch is in the off position.