I'll be very curious to hear this answer, because, since Hebrew is a revived language, I would expect musical keys to use the Latin alphabet. Indeed, even if it weren't, since languages that use the Cyrillic alphabet, or those like Chinese and Japanese that do not use an alphabet, use the Latin letters to designate keys. If the Hebrew letters are used, I would wonder whether this was an effort at universal hebraization or whether they related to some older system of Jewish music theory. Great question.
We use the neo-latin naming convention - https://en.wikipedia.org/wiki/Musical_note#12-tone_chromatic_scale , so do-re-mi-fa-sol-la-si-do.
So that's what's used for key signature names? So, like, if I see music with three flats in it, unless there's something weird happening I'm going to either call that E flat major or C minor. And if I'm playing guitar with my buddies, we might say something like "can we try that again in G?"
In those situations, are you still using the chromatic solfege naming? Would those be me (or maybe mi flat) major, do minor, and sol (major), respectively?
**I edited this before I submitted it, on account of I typed it out before I followed the Wikipedia link.
I'm sorry, I don't really understand the specific question - I'm not a music expert, I just learned how to play a couple of instruments when I was a kid.. :-) but from what I know, the names of the keys are according to that convention, yes. The names of the accords on the other hand used some other convention, I'm not sure if it was English or German.