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I welcome comments on the SETI Hacker conjecture particularly by credible experts who identify themselves and their affiliation and can explain their views quantitatively and with references to serious literature in a way I can follow. Comments are easier to digest if they don't start with some reference to a work of fiction, a comment about Microsoft or Apple, or "you idiot." Typically I do not respond to individuals but update the material below to reflect some of the critical comment.
I have not yet found one computer expert who believes it is possible to hack a computer without knowing something about its inner workings. They all think I am silly (at best). I have been surprised that in the face of such a consensus no technically-gifted contrarian has come forward and said "here's a way."
I am not a computer expert. I got my computing start on Illiac I (pre HAL in the SF metaphor) using the manual noted at the Sydney Illiac site. From the late fifties through the eighties I was involved with on-line work and large computers. I have since become dated. I have handled the analysis for my last two research projects using large Excel spread sheets. This can work for an astronomy investigation involving several hundred thousand sources, not for particles physics experiments.
|FAQs and comments
SETI Hacker motivation
conjecture as fiction
Interesting comments and observations
two different branches for the SETI Hacker conjecture. To
article "At least two
scenarios need to be considered in protecting against a
signal. One is a computer virus in the message that takes
the receiver. The other is an open message that gives an
code or instructions for a hardware translator to handle
message." Most comments have addressed the explicit
branch, where a virus downloads directly into the computer
involvement. The second scenario may be the more plausible
particularly in view of the serious criticisms of the
the comments seem to consider this branch and fewer still
questioned it. top
To enter a computer the virus must run but to run the virus must enter the computer. Put differently "If the software does not run it can't untangle inner workings. If it can't untangle inner workings it cannot run."This is the bootstrap problem that was mentioned in the article. It is a serious, perhaps the most serious, criticism of the explicit SETI Hacker conjecture.
All computer viruses work by
known systems and
As noted above, this view seems to
universally held by computer scientists. I have been
surprised by this
comment. In biological systems this does not seem to be
the other hand biological viruses have selectively
Must know exact form of
instructions and all other material
This is true for most earth
virus situations. The SETI Hacker conjecture suggests
of a small kernel that would somehow booststrap in, use
the kernel to
investigate the internal computer code and hardware and
code. This is a very big jump beyond what most experts
Only get one chance to penetrate
If the kernel is stored in the computer and bootstraps in it could have repeated chances. top
Modeling the SETI Hacker - earth-based computer relationshipMarcus Leech has prepared a thoughtful, many would say damning, critique of the explicit SETI Hacker conjecture. I have attached my annotated version. I understand that Leech is continuing to work on his model. I regard Leech's work as important. Further work on this could help to illuminate some of the factors that enter into this subject. Several obvious factors are the size of the instruction set and memory size. Leech has also drawn my attention to the International Obfuscated C Coding Competition. This competition is interesting both from the standpoint of SETI message size and the SETI Hacker conjecture. The contest is doing research on SETI messaging!
My Fermilab colleague, Bill
suggests "We ourselves
could provide a 1940s-level civilization with
instructions on how to
modern computers, and how to bootstrap manufacturing,
to do so. But we couldn't guarantee that their computers
Computers may be messy but there are some general principles that were recognized early in their development. Most additions beyond that have a basis in logic.
"Processor instructions (aka code) are stored in
reserved code segment with its own particularities"
My understanding is that in many contemporary computers allocation of data and program areas is handled by the operating system. Does this mean that during failures such as soft power failures some of these rules may be violated? Wikipedia contains a short discussion of this. For additional information see an article on stack overflow noted by Leech. top
It appears to me that over a fifty year period instruction sets have been somewhat invariant. There's a good reason for that, they are dealing in a universal language, arithmetic/logic with a relatively limited number of operations.
Byte size (using byte generically)
Some comments along this line are nicely abstracted in a quote from Daniel Joyce "Aliens can't even be sure we use trinary, or binary encoding, or some other form. Do we use network byte order, host byte order, are our numbers 1 or 2 s complement? What's the ISA? Intel, MIPS, Sparc, or Rigelean SP500? What if it's not even a 'normal' processor, but one tied to running a particular language well, like a LISP machine, or the old-school weird APL ones? How is their OS even supposed to start?"For Joyce's list the combinatorial total might be O(100) - O(10^5). This is no challenge to untangle to a code breaking or Google-like system. top
Carrigan and I published some
fiction many years ago in Analog, "The Siren Stars". Used
picked up at Amazon.com.
A beautiful illustration of the Analog Magazine cover by
version in March, 1970 is available. We
used fiction because I did not see any way to handle
discussion of the
Hacker conjecture in the main stream science literature.
in connection with the SETI Hacker conjecture include
Elliot's 1962 novel A
Sagan's 1985 Contact, Star
Trek: The Next
Generation Story, Contagion,Virus, and Independence
Parenthetically, my daughter, Caroline Carrigan, was Scotty's ex-wife (Pamela Denberg Doohan) in the celebrated and now notorious December 20, 1986 Saturday Night Live spoof of Star Trek that contained Shatner's famous refrain to the assembled Trekkies "get a life". Many SETI Hacker critics have made the same suggestion to me. top
"Can a calculator be infected with a virus through any series of mathematical operations? No."
It is actually easy to hang up calculators, for example, a division by zero in an iterative sequence is typically not trapped and will hang up the sequence. Maybe some of the SETI Hacker critics should also get a life. top