There might be something useful in here: A.D. Rubin and P. Honeyman, "Long Running Jobs in an Authenticated Environment," March 1993. [Proc. Fourth USENIX UNIX Security Symp., Monterey (September 1993).] http://www.citi.umich.edu/techreports/reports/citi-tr-93-1.pdf http://www.citi.umich.edu/techreports/reports/citi-tr-93-1.ps.gz