Authentification method for a communication network

An authentication method for a communication network, comprising:

• a registration step (P1) comprising:
• transmitting a registration request to a receiving end (C) by a requesting end (A);
• transmitting a first identification code (SIDA), a request key (KA), a preliminary registration code (Tsa), a set of pseudo identification codes (PID) and a set of emergency keys (Kem) to the requesting end (A), as performed by the receiving end (C), wherein the set of pseudo identification codes (PID) comprises a plurality of pseudo identification codes (pidj), wherein the set of emergency keys (Kem) comprises a plurality of emergency keys (Kem), and wherein one of the plurality of emergency keys (Kem) of the set of emergency keys (Kem) corresponds to one of the plurality of pseudo identification codes (pidj) of the set of pseudo identification codes (PID);
• and
• transmitting a second identification code (SIDB) and an inquiry key (KB) to an inquiry end (B), as performed by the receiving end (C);
• a first inquiry step (P2a) comprising following steps performed by the requesting end (A):
• generating a first arbitrary code (Na1) having a first predetermined value;
• performing an XOR operation between the first arbitrary code (Na1) and the request key (KA) to generate a first calculated code (NX1);
• setting a value of a hash function of a combined data of the first identification code (SIDA), the request key (KA), the first arbitrary code (Na1) and the preliminary registration code (Tsa) as a verification code (AIDA);
• combining the verification code (AIDA), the first calculated code (NX1) and the preliminary registration code (Tsa) as a first request code (R1a);
• and
• transmitting the first request code (R1a) to an inquiry end (B);
• a second inquiry step (P2b) comprising following steps performed by the inquiry end (B):
• generating a second arbitrary code (Nb1) having a second predetermined value;
• performing an XOR operation between the second arbitrary code (Nb1) and the inquiry key (KB) to generate a second calculated code (Ny1);
• setting a value of a hash function of a combined data of the first request code (R1a), the inquiry key (KB), the second arbitrary code (Nb1) and the second identification code (SIDB) as a first tested code (V1′);
• combining the first request code (R1a), the second identification code (SIDB), the first tested code (V1′) and the second calculated code (Ny1) as a second request code (R1b);
• and
• transmitting the second request code (R1b) to the receiving end (C);
• a first answering step (P3a) comprising following steps performed by the receiving end (C) if the preliminary registration code (Tsa) is verified to be correct by the receiving end (C):
• performing an XOR operation between the request key (KA) and the first calculated code (NX1) to generate a third arbitrary code (Na2) having the first predetermined value of the first arbitrary code (Na1);
• performing an XOR operation between the inquiry key (KB) and the second calculated code (Ny1) to generate a fourth arbitrary code (Nb2) having the second predetermined value of the second arbitrary code (Nb1);
• verifying the first tested code (V1′) with a determined value of the hash function of a combined data of the first request code (R1a), the inquiry key (KB), the fourth arbitrary code (Nb2) and the second identification code (SIDB);
• verifying the verification code (AIDA) with a determined value of the hash function of a combined data of the first identification code (SIDA), the request key (KA), the third arbitrary code (Na2) and the preliminary registration code (Tsa);
• wherein the first answering step (P3a) further comprises following steps performed by the receiving end (C) if both the first tested code (V1′) and the verification code (AIDA) are verified to be correct:
• generating a first authentication key (CK1);
• performing an XOR operation between the first authentication key (CK1) and a value of the hash function of a combined data of the request key (KA), the first identification code (SIDA) and the preliminary registration code (Tsa) to generate a first calculated verification code (NX1′);
• performing an XOR operation between the first authentication key (CK1) and a value of the hash function of a combined data of the inquiry key (KB) and the fourth arbitrary code (Nb2) to generate a second calculated verification code (Ny1′);
• setting a value of the hash function of a combined data of the second calculated verification code (Ny1′), the fourth arbitrary code (Nb2), the inquiry key (KB) and the second identification code (SIDB) as a second tested code (V2′);
• increasing a value of a variable (m) by an increment;
• setting the value of the variable (m) as a first new registration code (TSa1-new);
• performing an XOR operation between the first new registration code (Tsa1-new) and a value of the hash function of a combined data of the request key (KA), the first identification code (SIDA) and the third arbitrary code (Na2) to generate a final registration code (Ts);
• setting a value of the hash function of a combined data of the first calculated verification code (NX1′), the third arbitrary code (Na2), the final registration code (Ts), the request key (KA) and the first identification code (SIDA) as a third tested code (V3′);
• setting a value of the hash function of a combined data of the inquiry key (KB), the fourth arbitrary code (Nb2) and the second identification code (SIDB) as a first new inquiry key (KB1-new);
• updating the inquiry key (KB) with the first new inquiry key (KB1-new);
• setting a value of the hash function of a combined data of the request key (KA), the first identification code (SIDA) and the first new registration code (Tsa1-new) as a first new request key (KA1-new);
• updating the request key (KA) with the first new request key (KA1-new);
• combining the first calculated verification code (NX1′), the second calculated verification code (Ny1′), the second tested code (V2′), the third tested code (V3′) and the final registration code (Ts) as a first response code (R2a);
• and
• transmitting the first response code (R2a) to the inquiry end (B);
• a second answering step (P3b) comprising following steps performed by the inquiry end (B) if the second tested code (V2′) is verified to be correct using a determined value (V2—chk′) of the hash function of a combined data of the second calculated verification code (Ny1′), the second arbitrary code (Nb1), the inquiry key (KB) and the second identification code (SIDB):
• performing an XOR operation between the second calculated verification code (Ny1′) and a value of the hash function of a combined data of the inquiry key (KB) and the second arbitrary code (Nb1) to generate a second authentication key (CK2);
• setting a value of the hash function of a combined data of the inquiry key (KB), the second arbitrary code (Nb1) and the second identification code (SIDB) as a second new inquiry key (KB2-new);
• updating the inquiry key (KB) with the second new inquiry key (KB2-new);
• combining the first calculated verification code (NX1′), the third tested code (V3′) and the final registration code (Ts) as a second response code (R2b);
• and
• transmitting the second response code (R2b) to the requesting end (A);
• and
• a verification step (P4) comprising following steps performed by the requesting end (A) if the third tested code (V3′) is verified to be correct using a determined value (V3—chk′) of the hash function of a combined data of the first calculated verification code (NX1′), the first arbitrary code (Na1), the final registration code (Ts), the request key (KA) and the first identification code (SIDA):
• performing an XOR operation between the first calculated verification code (NX1′) and a value of the hash function of a combined data of the request key (KA), the first identification code (SIDA) and the preliminary registration code (Tsa) to generate a third authentication key (CK3);
• performing an XOR operation between the final registration code (Ts) and a value of the hash function of a combined data of the request key (KA), the first identification code (SIDA) and the first arbitrary code (Na1) to generate a second new registration code (Tsa2-new);
• setting a value of the hash function of a combined data of the request key (KA), the first identification code (SIDA) and the second new registration code (Tsa2-new) as a second new request key (KA2-new);
• updating the preliminary registration code (Tsa) with the second new registration code (Tsa2-new);
• and
• updating the request key (KA) with the second new request key (KA2-new).