practice

Doi: 10.1145/2018396.2018412

Article development led by queue.acm.org

The time has come for software liability laws.
By PouL-heNNiNG kamP
the software
industry is

the Problem

one SCore AnD seven years ago, Ken Thompson brought forth a new problem, conceived by thinking, and dedicated to the proposition that those who trusted computers were in deep trouble.

I am, of course, talking about Thompson’s 1984 ACM A.M. Turing Award Lecture—“Reflections on Trusting Trust.” 2 Unless you remember this piece by heart, you might want to take a moment to read it if at all possible ( http://bit.ly/nnGh5b).

The one sentence in Thompson’s lecture that really,
really matters is: “You can’t trust code that you did not
totally create yourself.”
This statement is not a matter of politics, opinion,
taste, or in any other way a value judgment; it is a
fundamental law of nature, which follows directly
from pure mathematics in the general vicinity of the
works of Turing and Gödel. If you doubt this, please
(at your convenience) read Douglas Hofstadter’s
classic Gödel, Escher, Bach, 1 and when you get to the

part about “Mr. Crab’s record player,” substitute “Mr. Crab’s laptop.”

IllustratIon by alex wIllIamson

Gödel, escher, Bach Hofstadter’s book, originally published in 1979, does not in any way detract from Ken Thompson’s fame, if, indeed, his lecture was inspired by it;