The only credibility I see to challenge here is the author of the claim... I see no credible evidence. The resolution of the image leaves little to be found. Also the STURP team has analyzed the image, especially the facial image, using microxrayspectrometry and did not find the "metals" of the inks she theorizes have been "transferred" to a crossword like pattern of aramaic letters across the face of the image. I simply find this hard to believe that you can even see such characters. I have not heard of them before this in any of the literature.
so you believe in the Shroud’s authenticity?