The concept of an unsigned integer is simple: it cannot be negative. Satoshi often used unsigned integers in the Bitcoin code, he commonly referenced them in his emails and they are used in the Bitcoin File Format (the subject of alleged copyright which Dr Wright claims to have authored). Searches undertaken by the Developers indicate they were used 294 times across the entirety of the original Bitcoin code and over 100 times in the original main.cpp, main.h and bignum.h. Their point was that Satoshi would not have forgotten what an unsigned integer was, even after 15 years.

In a striking passage of cross-examination, Dr Wright was unable to explain the concept (at least until after he was taken to ‘C++ for Dummies’). He was taken to the script.h file and to the declaration of a constant integer variable called MAX_SCRIPT_ELEMENT_SIZE. The cross-examination proceeded as follows:

4 Q. Just out of curiosity, do you know what unsigned means

5 in that?

6 A. I do. Basically it's unsigned variable, it's not an

7 integer with --

8 Q. With what?

9 A. It's larger. I'm not sure how -- I mean, on the stand

10 here, I'm not sure how I'd say it, but --

11 Q. Take a wild guess.

12 A. How I would describe it, I'm not quite sure. I know

13 what it is.

14 Q. Okay.

15 A. I'm not terribly good when I'm trying to do things like

16 this. Writing it down would be different.

17 Q. Well, do you recall you mentioned that you had a book by

18 Professor Stroustrup?

19 A. I do.

20 Q. You haven't disclosed that book, but you have disclosed

21 three other books about C++, so I want to take you to

22 one of those. It's {L1/199/1}, and could we go to

23 page 47 {L1/199/47}. Do you see that it explains that

24 "unsigned" means that it cannot be negative?

25 A. Yes, I do understand that. Would I have thought of

145: 1 saying it in such a simple way? No.”

Some of the pauses are indicated in the transcript but on being invited to take a wild guess, there was a long pause (of about 8 seconds, albeit not referenced in one version of the transcript) before Dr Wright started his answer (a strong contrast with his usual immediate answer to any question).

Bearing in mind the care, effort and skill which Satoshi used in writing the Bitcoin Source Code, I agree that Satoshi would not have had any difficulty in explaining the concept of an unsigned integer, even 15 years later. Accordingly, I agree with the Developers that this evidence indicates that Dr Wright did not write the Bitcoin Source Code. Furthermore, this was a legitimate point on which to cross-examine, bearing in mind Dr Wright’s much vaunted expertise in coding in C++, which he claimed still to be current. This claim has turned out to be one of many made by Dr Wright in this litigation which have common characteristics. A claim is made that he has a special (even unique) skill, knowledge or experience. The claim appears to be supported by some detail from the past which it is very difficult, if not impossible, to check or disprove, often because the detail is known only to him. Dr Wright is well aware of this. When he is challenged, he usually has some additional explanation which often involves some technical matters (which again are difficult or impossible to check or disprove during cross-examination). The claim is often either exaggerated or misleading or is simply untrue.