Anonymous social stamps: Authenticating anonymous statements to friends with privacy

Numerous online services and applications for smart devices exist today on the internet which claim almost similar functionalities. This inevitably leads to the problem of being able to choose the right one which is mostly done today by trial-and-error. However this gets tricky if it involves sharing privacy sensitive information with the service e.g. in the case of health and well-ness services. A customer´s trust in a new online service is known to increase based on testimonials (or observable behavior) of people within a social distance (friends, friends-of-friends etc). Linking testimonials to users requires releasing one´s social network information which by itself is privacy invasive. The paper presents the concept of an anonymous social stamp which can be assigned to anonymous statements and help prove that the statement was made by a particular member of an external social networking site. Trust can then be derived based on the social distance between the persons concerned: the person who made the statement and the person verifying the statement. A possible implementation of the concept is shown with the existing infrastructure of RSA keys already in use by social networking sites. The concept is applicable for the new services that can create confidence in new users by revealing anonymous data sharing configurations of other users with the service.