I was wondering about exactly what he did to transpose the cipher.

If you start with the 1st symbol, and then work backwards through the 1st column, that yields the column of 9 symbols shown on the bottom left of this image. So start with the H, move to the bottom and pick up the N, then continue up the column.

The final symbol is the backwards D, then moving one symbol to the right and working through the same process yields the next column, shown below.

Continuing with that through the 1st 9 columns gives this 9×9 formation of symbols.

Then repeating that same process through the remaining 8 columns yields the formation of symbols shown below on the right.

Then the columns from the formation of the symbols on the left become the odd columns.

And the symbols from the formation on the right become the even columns.

I guess I’m wondering if this is nothing more than a parlor trick, or maybe just a slight variation of the process doranchak described in his video, or if this is what he actually may have done.

I’m personally still looking for something a bit more elegant, but I wanted to share this because it illustrates how the columns actually remain intact after transposition, which I personally did not notice initially, and also I think it’s slightly less confusing to work through since all the wrap arounds are at the bottom, and there are no skips. It’s just moving one symbol over horizontally.

I also have not taken the time yet to see how the mistake in the bottom half would seem to tie in with this.

Anyway, I’m still tinkering with it, and I know the guys who solved it likely are already pretty certain what he did.

Have a nice Christmas everyone!