A method and an apparatus for identifying sensitive information identifier in a privacy-protection manner are provided. The method is performed at a first computing entity which is configured to access a set of license plate numbers and to communicate with a second computing entity which is configured to obtain a license plate number that is captured by one of one or more license plate recognition (LPR) devices distributed in a certain geographic area. The method comprises: receiving a first hash value of the license plate number from the second computing entity; determining that the first hash value matches a second hash value of a plurality of hash values in an association relationship; and generating a notification of an identified license plate number. The association relationship maps a respective one of the plurality of hash values to a corresponding license plate number in the set of license plate numbers.