  Voluntary donation of private information for altruistic purposes, such as
advancing research, is common. However, concerns about data misuse and leakage
may deter individuals from donating their information. While prior research has
indicated that Privacy Enhancement Technologies (PETs) can alleviate these
concerns, the extent to which these techniques influence willingness to donate
data remains unclear.
  This study conducts a vignette survey (N=485) to examine people's willingness
to donate medical data for developing new treatments under four privacy
guarantees: data expiration, anonymization, use restriction, and access
control. The study explores two mechanisms for verifying these guarantees:
self-auditing and expert auditing, and evaluates the impact on two types of
data recipient entities: for-profit and non-profit institutions.
  Our findings reveal that the type of entity collecting data strongly
influences respondents' privacy expectations, which in part influence their
willingness to donate data. Respondents have such high expectations of the
privacy provided by non-profit entities that explicitly stating the privacy
protections provided makes little adjustment to those expectations. In
contrast, statements about privacy bring respondents' expectations of the
privacy provided by for-profit entities nearly in-line with non-profit
expectations. We highlight the risks of these respective results as well as the
need for future research to better align technical community and end-user
perceptions about the effectiveness of auditing PETs and to effectively set
expectations about the efficacy of PETs in the face of end-user concerns about
data breaches.
