Alex Bellos reports:
Rachel is a student at a US university who was sexually assaulted on campus. She decided against reporting it (fewer than 10% of survivors do). What she did, however, was register the assault on a website that is using novel ideas from cryptography to help catch serial sexual predators.
The organisation Callisto lets a survivor enter their name in a database, together with identifying details of their assailant, such as social media handle or phone number. These details are encrypted, meaning that the identities of the survivor and the perpetrator are anonymous. If you hacked into the database, there is no way to identify either party.
However, if the same perpetrator is named by two people, the website registers a match and this triggers an email to two lawyers. Each lawyer receives the name of one of the survivors (but not the name of the perpetrator). The lawyers then contact the survivors to let them know of the match and offer to help coordinate any further action should they wish to pursue it.
Read more at The Guardian.