Recent am tradus o astfel de adeverinta - nu se chema adeverinta de autenticitate, dar scopul era acelasi, si anume de a confirma autenticitatea diplomei eliberate catre... cu nr... la data ... etc. Titlul documentului era "Adeverinta", asa ca am tradus simplu prin "Certificate". Daca doresti neaparat, cred ca ii poti spune "Authentication Certificates" sau "Certificate of Authenticity"
Ambele sunt corecte (cel putin din punct de vedere gramatical:D)
"The U.S. Department of State issues both Authentication Certificates and Apostilles. (...) In accordance with 22 CFR, Part 131, the Office of Authentications provides signed certificates of authenticity for a variety of documents to individuals, institutions, and government agencies. Examples of documents that may require authentication for use abroad may include, but are not limited to, company bylaws, powers of attorney, trademarks, diplomas, treaties, warrants, extraditions, agreements, certificates of good standing, and courier letters.
http://travel.state.gov/content/travel/english/legal-conside...