Method and system for storing, retrieving, and managing data for tags
This invention relates generally to a method and system for storing, retrieving, and managing data for tags that are associated in some manner to any type of object. More particularly, the present invention writes data to these tags, reads data from these tags, and manages data that is written to and/or read from these tags.
1. A method for generating an alarm when one or more tags fall within a proximity comprising:
receiving a first message on a tag that includes a tag audible alarm, that is broadcast at a regular time interval from a partner tag using a partner timer interrupt on the partner tag that includes a partner tag audible alarm, and that includes a partner identifier of the partner tag that is used to distinguish the partner tag from other tags and a first broadcast time that is the time the first message is broadcast from the partner tag;
reading the partner identifier and the first broadcast time of the partner tag from said first message on the tag;
sounding an alarm on the tag audible alarm of the tag if said read partner identifier is in a list of sensitive tags on the tag only if the first broadcast time in the first message is within a predetermined time period in order to prevent a replay attack; and
broadcasting from the tag a second message that includes an identifier of the tag and a second broadcast time that is the time the second message is broadcast from the partner tag at the same regular time interval using a timer interrupt on the tag that the partner tag receives and uses to sound an alarm on the partner tag audible alarm of the partner tag if the identifier is in a partner list of sensitive tags on the partner tag only if the second broadcast time in the second message is within a predetermined time period in order to prevent a replay attack, wherein the identifier is used to distinguish the tag from other tags.
2. The method for generating an alarm as in claim 1 wherein said sounding an alarm step is performed only if a signature in said first message verifies.
3. The method for generating an alarm as in claim 1 wherein said predetermined period is not more than one minute from a current time.