Method of storing and retrieving a sensitive information (CC#), said information (CC#) requiring to be secured in an environment comprising a plurality of application systems (ASi i=1..n) that can use said information (CC#), characterized in that storing said information (CC#) comprises the following steps: • at a given application system (AS j) of said plurality of application systems (ASi i=1..n): - receiving said information (CC#), - generating from said information (CC#) an extracted data (C(CC#)) and a complementary data (A(CC#)), such that said extracted data (C(CC#)) and said complementary data (A(CC#)) taken independently being insufficient for using said information (CC#) and such that said information (CC#) can be generated from said extracted (C(CC#)) and complementary data (A(CC#)) taken together, - generating an encoded information (H(CC#)) from said information (CC#), the step of generating an encoded information (H(CC#)) including computing a hashed value of the information (CC#) through a hash function, - sending the extracted data (C(CC#)) and the encoded information (H(CC#)) to a server system, • at the server system: - generating an index and assigning this index to the encoded information (H(CC#)) and the extracted data (C(CC#)), - storing the encoded information (H(CC#)), the extracted data (C(CC#)), and the index in a database (DB ss) associated to the server system (23, 24), - forwarding the index to said given application system (AS j) of the plurality of application systems (ASi i=1..n), • at said given application system (AS j): - assigning the index to the complementary data (A(CC#)), - storing the index along with said complementary data (A(CC#)) in a database (DB Asj) associated to said given application system (AS j). • at a given application system (AS j) of said plurality of application systems (ASi i=1..n): - receiving said information (CC#), - generating from said information (CC#) an extracted data (C(CC#)) and a complementary data (A(CC#)), such that said extracted data (C(CC#)) and said complementary data (A(CC#)) taken independently being insufficient for using said information (CC#) and such that said information (CC#) can be generated from said extracted (C(CC#)) and complementary data (A(CC#)) taken together, - generating an encoded information (H(CC#)) from said information (CC#), the step of generating an encoded information (H(CC#)) including computing a hashed value of the information (CC#) through a hash function, - sending the extracted data (C(CC#)) and the encoded information (H(CC#)) to a server system, - receiving said information (CC#), - generating from said information (CC#) an extracted data (C(CC#)) and a complementary data (A(CC#)), such that said extracted data (C(CC#)) and said complementary data (A(CC#)) taken independently being insufficient for using said information (CC#) and such that said information (CC#) can be generated from said extracted (C(CC#)) and complementary data (A(CC#)) taken together, - generating an encoded information (H(CC#)) from said information (CC#), the step of generating an encoded information (H(CC#)) including computing a hashed value of the information (CC#) through a hash function, - sending the extracted data (C(CC#)) and the encoded information (H(CC#)) to a server system, • at the server system: - generating an index and assigning this index to the encoded information (H(CC#)) and the extracted data (C(CC#)), - storing the encoded information (H(CC#)), the extracted data (C(CC#)), and the index in a database (DB ss) associated to the server system (23, 24), - forwarding the index to said given application system (AS j) of the plurality of application systems (ASi i=1..n), - generating an index and assigning this index to the encoded information (H(CC#)) and the extracted data (C(CC#)), - storing the encoded information (H(CC#)), the extracted data (C(CC#)), and the index in a database (DB ss) associated to the server system (23, 24), - forwarding the index to said given application system (AS j) of the plurality of application systems (ASi i=1..n), • at said given application system (AS j): - assigning the index to the complementary data (A(CC#)), - storing the index along with said complementary data (A(CC#)) in a database (DB Asj) associated to said given application system (AS j). - assigning the index to the complementary data (A(CC#)), - storing the index along with said complementary data (A(CC#)) in a database (DB Asj) associated to said given application system (AS j).