"adVERsary"?

[Geoffrey Nunberg]

I had the following question from someone I know at Microsoft. I've
never heard the "adVERsary" pron, and the OED gives only a version
with first-syllable stress. Is this simply a mistake, or what?

Geoff Nunberg
>
>I've noticed a strange phenomenon in the crypto community.  When
>describing cryptographic protocols, it seems that most people in the
>field talk about adVERsaries.  I first heard this from non-native
>English speakers, so I just took it to be a mispronunciation.  But I
>then started hearing native-born Americans saying adVERsary too.  I
>guessed that Americans started imitating some influential foreigner or
>foreigners in the field.  When asked, many Americans seem to think
>that adVERsary is simply a British pronunciation.  My inquiries have
>turned up Brits who claim that this is the standard British
>pronunciation, and ones who say they've never heard anything but
>ADversary.  Ditto for Aussies.  I've checked about eight dictionaries
>and none has given any pronunciation except ADversary.  Do you know
>what the story is?