This question already has an answer here:
This is a short story I read about 20-25 years ago.
The plot had three mercenaries, hired to deactivate the defenses on an ancient warship found mothballed in space. The captain of the merceneries was a human woman, and her two colleagues were aliens - I vaguely remember them being cat-like.
The ship was mothballed a long time before, and its computer was left to defend it - it's using the ships weapons to stop itself being boarded. The mercenaries manage to talk to the computer and get some hints as to the code they need to turn the defenses off again, though they can't talk their way on board. So they start broadcasting every combination that it might be while trying to figure out another plan. But they've only got a week to solve the problem, or they don't get paid, and there are too many possible codes to go through them all in time.
In the end
one of them realises that the deactivation code is 'Halti', which is - apparently - the Esperanto for 'Stop'
I've tried to find it off and on for years, but with no success - I have the feeling it's part of a wider series of stories. I'm almost sure I've not dreamed it.