TY - JOUR N2 - User authentication is an essential element of any communication system. The paper investigates the vulnerability of the recently published first semiquantum identity authentication protocol (Quantum Information Processing 18: 197, 2019) to the introduced herein multisession attacks. The impersonation of the legitimate parties by a proper combination of phishing techniques is demonstrated. The improved version that closes the identified loophole is also introduced L1 - http://www.czasopisma.pan.pl/Content/119991/PDF/28_02101_Bpast.No.69(4)_27.08.21_druk.pdf L2 - http://www.czasopisma.pan.pl/Content/119991 PY - 2021 IS - 4 EP - e137729 DO - 10.24425/bpasts.2021.137729 KW - quantum cryptography KW - quantum identity authentication KW - semi-quantum communication A1 - Zawadzki, Piotr VL - 69 DA - 26.06.2021 T1 - Semiquantum authentication of users resistant to multisession attacks SP - e137729 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/119991 T2 - Bulletin of the Polish Academy of Sciences Technical Sciences ER -