If you have enough sample data you could, in theory, crack the cipher. So the answer to your question is, technically, yes.
But we have rotating keys in WPA/WPA2 encryption now and this was far more prevalent when we used WEP encryption.

Cursor flashing: I believe this is done on the client side.  I often have a flashing cursor and no terminal session when my WAN connection fails and I have an SSH session open.

—
Ryan

> On Dec 11, 2014, at 9:27 PM, gregrwm <tclug1 at whitleymott.net> wrote:
> 
> a security advisory i read within the last couple months was all about how someone on a cafe wifi could fairly easily get into supposedly secure connections by repeatedly injecting crafted contents and thus cracking the cipher, something like that, can anyone clarify this with a pointer?  not sure but i think ssh was involved.  which got me to thinking, couldn't predictably repeating contents, eg a flashing cursor via ssh/vnc, also similarly provide a fairly easily crackable sequence, with no need for an observer to even inject anything?
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