Biblio

To help users create stronger text-based passwords, many web sites have deployed password meters that provide visual feedback on password strength. Although these meters are in wide use, their effects on the security and usability of passwords have not been well studied.

We present a 2,931-subject study of password creation in the presence of 14 password meters. We found that meters with a variety of visual appearances led users to create longer passwords. However, significant increases in resistance to a password-cracking algorithm were only achieved using meters that scored passwords stringently. These stringent meters also led participants to include more digits, symbols, and uppercase letters.

Password meters also affected the act of password creation. Participants who saw stringent meters spent longer creating their password and were more likely to change their password while entering it, yet they were also more likely to find the password meter annoying. However, the most stringent meter and those without visual bars caused participants to place less importance on satisfying the meter. Participants who saw more lenient meters tried to fill the meter and were averse to choosing passwords a meter deemed "bad" or "poor." Our findings can serve as guidelines for administrators seeking to nudge users towards stronger passwords.

Sandboxes impose a security policy, isolating applications
and their components from the rest of a system. While
many sandboxing techniques exist, state of the art sandboxes
generally perform their functions within the system
that is being defended. As a result, when the sandbox fails
or is bypassed, the security of the surrounding system can
no longer be assured. We experiment with the idea of innimbo
sandboxing, encapsulating untrusted computations
away from the system we are trying to protect. The idea
is to delegate computations that may be vulnerable or malicious
to virtual machine instances in a cloud computing
environment.
This may not reduce the possibility of an in-situ sandbox
compromise, but it could significantly reduce the consequences
should that possibility be realized. To achieve this
advantage, there are additional requirements, including: (1)
A regulated channel between the local and cloud environments
that supports interaction with the encapsulated application,
(2) Performance design that acceptably minimizes
latencies in excess of the in-situ baseline.
To test the feasibility of the idea, we built an in-nimbo
sandbox for Adobe Reader, an application that historically
has been subject to significant attacks. We undertook a
prototype deployment with PDF users in a large aerospace
firm. In addition to thwarting several examples of existing
PDF-based malware, we found that the added increment of
latency, perhaps surprisingly, does not overly impair the