07-05-2015 дата публикации
Номер: US20150122898A1
Принадлежит:
The circuitry introduced in this invention selectively slows down the functioning of an electronic circuit maintaining a particular state for a prolonged period of time. This circuitry is used not only to achieve the desired effect in maintaining security from electronic thieves trying to circumvent codes but also in other applications such as enabling a circuit to continue to function in the event of a brief loss of power. For example, in an RFID system, if a reader is frequency hopping, a tag loses power for as long as about 400 milliseconds when the reader changes to other frequencies. In a preferred embodiment, the disclosed circuitry is used in conjunction with a destruct sequence. 1receiving a first code transmitted by an RFID reader, the first code generated by an XOR calculation;comparing a second code within the tag to the first code;if the first code and second code do not match, muting by the tag; andif the first code and second code match, transmitting by the tag a third code to the RFID reader.. A method for a radio frequency identification (RFID) tag comprising: This application is a continuation of and claims priority from co-pending U.S. patent application Ser. No. 13/900,296, filed on May 22, 2013, which is a continuation of U.S. patent application Ser. No. 13/276,222, filed Oct. 18, 2011, which issued as U.S. Pat. No. 8,464,957 on Jun. 18, 2013, which is a continuation of and claims priority from Ser. No. 12/111,140, filed Apr. 28, 2008, which issued as U.S. Pat. No. 8,056,818 on Nov. 15, 2011, which is a continuation of and claims priority from U.S. patent application Ser. No. 11/264,573, filed Oct. 31, 2005, which issued as U.S. Pat. No. 7,377,445 on May 27, 2008, which is a continuation of and claims priority from U.S. patent application Ser. No. 11/153,030 filed on Jun. 14, 2005, which issued as U.S. Pat. No. 7,364,084 on Apr. 29, 2008, which is a divisional application of and claims priority from U.S. patent application Ser. No. 10/140,589 ...
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