Method and apparatus for anonymously identifying sensitive information identifiers

An apparatus comprising 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 devices distributed in a certain geographic area, the first computing entity comprising a processor configured to:

• receive a first hash value of the license plate number from the second computing entity;
• determine that the first hash value matches a second hash value of a plurality of hash values in an association relationship that maps a respective one of the plurality of hash values to a corresponding license plate number in the set of license plate numbers, each of the plurality of hash values having been generated by implementing a hash algorithm on the corresponding license plate number;
• and
• generate a notification of an identified license plate number, the identified license plate number being identified from the association relationship as corresponding to the first hash value that matches the second hash value.

An apparatus comprising 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 devices distributed in a certain geographic area, the first computing entity comprising a processor configured to:

• receive a first subset of digits of a first obfuscated value from the second computing entity, wherein the first obfuscated value corresponds to the license plate number;
• identify at least one second obfuscated value from a plurality of second obfuscated values, wherein each of the at least one second obfuscated value includes the first subset of digits of the first obfuscated value;
• send a second subset of digits of each of the identified at least one second obfuscated value to the second computing entity;
• receive, from the second computing entity, a message indicating that a certain obfuscated value of the identified at least one second obfuscated value matches the first obfuscated value;
• and
• generate a notification of an identified license plate number, the identified license plate number being identified from an association relationship as corresponding to the certain obfuscated value of the identified at least one second obfuscated value that matches the first obfuscated value, wherein the association relationship maps a respective one of the plurality of second obfuscated values to a corresponding license plate number of the set of license plate numbers.

An apparatus comprising a first computing entity which is configured to access a second plurality 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 devices distributed in a certain geographic area, the first computing entity comprising a processor configured to:

• receive a first encrypted license plate number from the second computing entity, the first encrypted license plate number being generated by encrypting the license plate number with a first key using a commutative encryption algorithm;
• generate a second encrypted license plate number by encrypting the first encrypted license plate number with a second key using the commutative encryption algorithm;
• determine that the second encrypted license plate number matches a doubly encrypted license plate number in a doubly encrypted list that maps a respective one of a first plurality of doubly encrypted license plate numbers to a corresponding one of the second plurality of license plate numbers;
• and
• generate a notification of an identified license plate number, the identified license plate number being identified from the doubly encrypted list as corresponding to the second encrypted license plate number that matches the doubly encrypted license plate number.