Conventional authentication systems, that are used to protect most modern mobile
applications, are faced with usability and security problems related to their static and one …

The advent of end-to-end encrypted (E2EE) messaging and backup services has brought
new challenges for usable authentication. Compared to regular web services, the nature of …

Our everyday life depends more and more on online services and, therefore, access to
related user accounts. The security of user accounts, again, is tied to the security of the …

Digital transformation with the adoption of cloud technologies, outsourcing, and working‐
from‐home possibilities permits flexibility for organizations and persons. At the same time, it …

In this paper, we propose a new digital signature primitive, called expander signature, and
discuss its application in blockchain. The most promising advantage of expander signature …

As account compromises and malicious online attacks are on the rise, multi-factor
authentication (MFA) has been adopted to defend against these attacks. OTP and mobile …

With the rise in sophisticated cyber threats, traditional authentication methods are no longer
sufficient. Risk-based authentication (RBA) plays a critical role in the context of the zero trust …

Risk-based authentication (RBA) aims to protect end-users against attacks involving stolen
or otherwise guessed passwords without requiring a second authentication method all the …

Cybercriminals controlling multiple accounts to conduct malicious activities are a threat to
the security of online services. These accounts form malicious communities that are difficult …

Online services have difficulties to replace passwords with more secure user authentication
mechanisms, such as Two-Factor Authentication (2FA). This is partly due to the fact that …