List of free rfc3161 servers.

rfc3161.txt

http://sha256timestamp.ws.symantec.com/sha256/timestamp
http://timestamp.globalsign.com/scripts/timstamp.dll
https://timestamp.geotrust.com/tsa
http://timestamp.verisign.com/scripts/timstamp.dll 
http://timestamp.comodoca.com/rfc3161
http://timestamp.wosign.com
http://tsa.startssl.com/rfc3161
http://time.certum.pl
http://timestamp.digicert.com
https://freetsa.org
http://dse200.ncipher.com/TSS/HttpTspServer
http://tsa.safecreative.org
http://zeitstempel.dfn.de
https://ca.signfiles.com/tsa/get.aspx
http://services.globaltrustfinder.com/adss/tsa
https://tsp.iaik.tugraz.at/tsp/TspRequest
http://timestamp.apple.com/ts01
http://timestamp.entrust.net/TSS/RFC3161sha2TS

I'm finding a free TSA that optimized for Asia users.
Do you know any?

(All above servers take at least 200ms for a ping response)

PS: The first server I've found is: http://tsa.wotrus.com (~75ms)

I finded new TSA server. You can use

http://oscp.cocbuilder.su/tsa.php

@Manouchehri ,,

Thanks for compiling this list.

My interest is in free general-purpose timestamping service (e.g. stamping pdf, zip files) and this page was near the top of Google's search results, so a good starting point for a comprehensive list of freeTSA servers, but some of the links appear to be dead

dse200.ncipher.com/TSS/HttpTspServer : address could not be found for either the full URL or the base address dse200.ncipher.com.

timestamp.geotrust.com/tsa : has been retired by Symantec and replaced with sha256timestamp.ws.symantec.com/sha256/timestamp (see INFORMATIONAL | Discontinued Use of (Legacy) SHA1 RFC 3161 timestamp service - DigiCert) and appears to be a direct link to their RFC3161 timestamper and not a "landing" page.

Not 100% certain but it looks like the "timestamp.dll" links are direct RFC3161 timestamp server links designed to be used for code-signing only (possibly by Microsoft's SignTool).

For what I came to this page for the best current (1/19/2019) link for genuinely free general-purpose timestamping is freetsa.org. No time to go through all the links, but this of interest so I will update this comment as time allows.

Thanks again for the scholarship compiling this resource.

Excellent resource! Is anyone generating, signing and timestamping PDFs on the fly? Currently working with TCPDF which signs ok but does not have time stamping implemented.

http://timestamp.entrust.net/TSS/RFC3161sha2TS

@jonybuzz Thanks, added.

@haleba-hotmail dse200.ncipher.com still resolves fine here. Could you try again?

@seagate00 Getting a connection refused for http://oscp.cocbuilder.su/tsa.php.

@Manouchehri

Double checked and it looks like the ncipher link is purely a timestamping server to be accessed via software like openssl and not a web site based service like freetsa, so simply putting the base address in a browser yields a "no page found" error, but it resolves fine in tracert.

Looks like http://timestamp.globalsign.com/scripts/timstamp.dll is now paid product.

GlobalSign's trusted timestamping Software as a Service (SaaS) provides a low cost and easy method

http://tsa.startssl.com/rfc3161
http://tsp.iaik.tugraz.at/tsp/TspRequest
Can be removed from the list. While they get sign successfully, they aren't trusted by windows.

It appears that http://timestamp.verisign.com/scripts/timstamp.dll no longer functions.

Edit: The downtime of the verisign service was temporary, and it came back online a few hours after going down.