<div dir="ltr"><span id="gmail-docs-internal-guid-dca2abfe-7fff-0dca-5430-26d7299bab48"><p style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="background-color:transparent;color:rgb(0,0,0);font-family:Arial;white-space:pre-wrap">Hello Tor-Dev,</span><br></p><br><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">My name is Alex Mages, and I have been doing pluggable transport research with Eugene Vasserman (CC) at Kansas State University.</span></p><br><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">Right now we're exploring latency-based attacks but are having trouble achieving a particular goal: a way to “ping” an arbitrary node in a client’s already-built (“live”) circuit. One-way timing is ideal but round trip time would suffice. We can glean this information during circuit construction, but what about a “live” circuit? Ideally, this would be a periodic thing Tor already keeps track of, but as an on-demand or as a byproduct/side-effect of a different function would also work. We have not been able to find a way to do this within the Tor (sub)protocol specs or the control port spec.</span></p><br><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">Any ideas, suggestions, or criticisms would be greatly appreciated.</span></p><br><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">Thanks,</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;vertical-align:baseline;white-space:pre-wrap">Alex Mages</span></p></span></div>