Photios I of Constantinople
The text of the Protest appears to have survived largely through attribution to Athanasius of Alexandria. In the way of attestation Patriarch Photios I of Constantinople in his "Bibliotheca" is closer to the mark in ascribing it to Theodoret. Euthymios Zigabenos cites without naming an author, but Severus of Antioch in his Contra Impium Grammaticum quotes from with attribution to Eutherius of Tyana. (Both the latter authors are referring to chapter 20, which together with 21 may well constitute a slightly later addition by Eutherius to his original text).