1. Secure Statistics Software Francisco Vera National Institute of Statistical Sciences

2. Secure Sums Secure sum protocol (explained by Alan) –Process starts at one agency –A message is passed from agency to agency sequentially –If agencies know order of sequence, they could collide and break confidentiality. Third party server handles communication and sequence order

3. Double Encryption Server carries the messages between agencies, but is unable to read them –Agencies encrypt messages and share key with each other but not with server Communication between server and agencies is encrypted –During login, server assigns tag and encryption key, which is not shared with other agencies

4. Reservation Some one designated by involved agencies reserves the server The server waits until all involved agencies are logged in and ready When all agencies are ready, server randomizes order of agencies and start process

5. Regression Similar to secure sum implementation Agencies agree upon formula They all should have variables involved in regression with the same names Formula builder Regression results: binary file containing XtX, XtY, YtY Regression results viewer

6. Screen Shoots

17. Demo Run program