J. G. Cederquist Ricardo Corin Muhammad Torabi Dashti On the Quest for Impartiality: Design and Analysis of a Fair Non-repudiation Protocol. 27-39 2005 conf/icics/2005 ICICS http://dx.doi.org/10.1007/11602897_3 db/conf/icics/icics2005.html#CederquistCD05