Dear Markus,
Is there some pdftex option to suppress this PTEX.Fullbanner string in the document catalog entirely, along with the Producer key in the info dictionary, or at least to make sure that such strings do not leak any version numbers or other time-variable information into the PDF?
In TeX Live 2016, some changes are made: (1) If an environment variable SOURCE_DATE_EPOCH is set like SOURCE_DATE_EPOCH=1456304783, it is used as the time and pdf may become unique. (2) New primitives \pdfinfoomitdate and \pdftrailerid. If \pdfinfoomitdate=1, date is omitted. If \pdftrailerid{somestring}, somestring is used as the trailer. It can be \pdftrailerid{}. These may also be used to obtain unique pdf. (3) A new primitive \pdfsuppressptexinfo. The default is \pdfsuppressptexinfo=0. [1] if \pdfsuppressptexinfo & 1 != 0 there is not a line /PTEX.Fullbanner (This is pdfTeX, ... ...) in an output pdf. [2] if \pdfsuppressptexinfo & 2 != 0 there is not a line /PTEX.FileName (... ...) in an output pdf. [3] if \pdfsuppressptexinfo & 4 != 0 there is not a line /PTEX.PageNumber ... in an output pdf. [4] if \pdfsuppressptexinfo & 8 != 0 there is not a line /PTEX.InfoDict ... ... in an output pdf. Best, Akira