Authors:
Roberto Van Eeden
1
;
Matteo Paier
1
;
2
and
Marino Miculan
1
;
3
Affiliations:
1
University of Udine, Dept. of Mathematics, Computer Science and Physics, Italy
;
2
IMT School for Advanced Studies, Lucca, Italy
;
3
Ca’ Foscari University of Venice, Dept. of Environmental Sciences, Informatics and Statistics, Italy
Keyword(s):
Formal Methods, Security Protocols, Digital Identity, Identity Management.
Abstract:
We analyze the security of Level 2 multi-factor authentication (MFA) based on SMS One-Time Passcode (OTP) of Italian Electronic Identity Card (CIE). We propose a novel threat model encompassing password compromise, network disruptions, user errors, and malware attacks. The combinations of the adversary’s attack capabilites yield a plethora of possible attack scenarios, which we systematically generate, formalise and verify in ProVerif. Our analysis reveals that CIE MFA based on SMS OTP is vulnerable to attacks with read access to the mobile device or keyboard, or to phishing, but event to mere read access to the user’s computer screen. To address the latter vulnerability, we propose a minor modification of the protocol. The threat model we introduce paves the way for the analysis of other CIE MFA protocols.