What should be done in case of a change of surname? Can I still use my e-signature?
In case of surname change, you cannot use your e-signature kit. You need to renew your e-signature kit with a request for information updates.
You can get relevant information from the link http://faq.cc.metu.edu.tr/faq/i-lost-my-e-signature-it-was-stolen-my-credentials-have-been-updated-what-should-i-do