Dirk Balfanz
Research Areas
      Authored Publications
    
  
  
  
    
    
  
      
        Sort By
        
        
    
    
        
        
          
              Preview abstract
          
          
              The security of online user accounts is often protected
by no more than a weak password. We present “Security Key”, a second-factor device based on open standards that protects users against phishing and man-in-the-middle attacks. The user carries a single device and
can self-register it with any online web service that supports the standard. The devices are simple to implement
and deploy, are not encumbered by patents, are simple to
use, privacy preserving, and secure against strong attackers. We have shipped support for Security Keys in one of
the mainstream web browsers. In addition, multiple device vendors produce security keys.
In this work, we demonstrate that Security Keys lead
to both an increased level of security and user satisfaction by analyzing a two year deployment which began
within our 50,000 person corporation and has extended
to our consumer-facing web applications. The Security
Key design has been standardized by the FIDO Alliance,
an organization with more than 170 member companies
spanning the industry.
              
  
View details
          
        
      
    
        
          
            
              Origin-Bound Certificates: A Fresh Approach to Strong Client Authentication for the Web
            
          
        
        
          
            
              
                
                  
                    
    
    
    
    
    
                      
                        Michael Dietz
                      
                    
                
              
            
              
                
                  
                    
                    
                      
                        Alexei Czeskis
                      
                    
                  
              
            
              
                
                  
                    
                    
                  
              
            
              
                
                  
                    
                    
                      
                        Dan Wallach
                      
                    
                  
              
            
          
          
          
          
            21st USENIX Security Symposium, The USENIX Association (2012), pp. 317-332
          
          
        
        
        
          
              Preview abstract
          
          
              Client authentication on the web has remained in the internet-equivalent of the stone ages for the last two decades. Instead of adopting modern public-key-based authentication mechanisms, we seem to be stuck with passwords and cookies.
In this paper, we propose to break this stalemate by presenting a fresh approach to public-key-based client authentication on the web. We describe a simple TLS extension that allows clients to establish strong authenti- cated channels with servers and to bind existing authen- tication tokens like HTTP cookies to such channels. This allows much of the existing infrastructure of the web to remain unchanged, while at the same time strengthening client authentication considerably against a wide range of attacks.
We implemented our system in Google Chrome and Google’s web serving infrastructure, and provide a per- formance evaluation of this implementation.
              
  
View details