发明名称 |
A KEYPAD DEVICE SECURITY SYSTEM AND METHOD |
摘要 |
The present invention increases the difficulty of interpreting electromagnetic emissions from a keypad system by facilitating randomness in the electromagnetic emissions associated with a particular key activation. A keypad security circuit utilizes a set of digital values that varies over both time and the bits as a keypad driver word applied to a keypad attribute (e.g., a row or column). The keypad security system of the present invention drives the varying strong keypad driver signal to an attribute of a keypad switch matrix (e.g., the rows or columns), applies an independently configured weak driver signals to the opposing attribute of the keypad switch matrix, retrieves a resulting signal from the opposing attribute, and interprets the results to determine if a switch included in a keypad system was activated (e.g., a key is pressed). |
申请公布号 |
WO02091143(A2) |
申请公布日期 |
2002.11.14 |
申请号 |
WO2002IB01547 |
申请日期 |
2002.04.29 |
申请人 |
KONINKLIJKE PHILIPS ELECTRONICS N.V. |
发明人 |
SETHIA, RAJEEV;BUER, MARK;STORY, FRANKLYN |
分类号 |
G06F3/02;G06F1/00;G06F21/00;H04L9/10 |
主分类号 |
G06F3/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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