[Spambayes] Re: egregious patents on anti-spam techniques
(Kaitlin Duck Sherwood)
rod at borderware.com
Thu Jan 30 18:29:13 EST 2003
Gary Robinson wrote:
>>Patent application on adaptive spam filtering:
>I looked at this last night.
>I am not a lawyer, so don't go to the bank on what I say. And I didn't spend
>a huge amount of time on it.
>But I do have some experience with patents, and I do understand the
>spambayes approach and the gist of their approach. It is my impression that
>the patent does not have a scope that encompasses Graham-derived filters,
>because they do not calculate "first" and "second" "symantic anchors" as the
>term is used in Claim 1.
Here's a quote from the background section of the application:
"Latent semantic analysis (LSA) is a method that automatically uncovers
the salient semantic relationships between words and documents in a
given corpus. Discrete words are mapped onto a continuous semantic
vector space, in which clustering techniques may be applied."
Graham derived filters do map words into a 'continuous semantic vector
space', namely the one dimensional vector
space of the range of [0.0, 1.0] of real numbers, and then 'clustering
techniques' are applied. Normally clusters are
defined by hyperplanes in N-Space, but in one dimesion they would be
threshold values. The two 'symantic anchors' are arguably cluster
centers located at 0.0 and 1.0 (also known as ham and spam in
In fact it is quite reasonable to describe a Graham-derived filter as
having a 'ham anchor' that can
be described as a location in N-Space in which each token string
describes a dimension and the
'clue' value for that string is the location of the anchor in that
dimension. Connecting the 'ham anchor'
in N-Space with the 'spam anchor' in N'-Space with a normalized vector
of unit length and positioning
a hyperplane at some position along the vector and perpendicular to it
(i.e. a threshold) is dead normal
practice in 'clustering techniques'.
I'd like to write this patent off too, but to me it looks like it likely
would apply to Graham-derived filters.
I'm not an expert in patents either, but I have a few issued ones of my own.
The good news is the filing date is June 14, 2001.
I'd like to suggest that it would be good to file a protest as Kaitlin
suggested. There was certainly
work done in this area before June 14, 2001. Does anyone have pointers
they can pass along.
Kaitlin Duck Sherwood wrote:
> To protest a patent, you need to file prior art (within 60 days!)
with the patent office. See:
> Patent application on adaptive spam filtering:
> Patent application on whitelists, blacklists, challenge-response, and
digital signatures used in spam-fighting:
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