Proving your Jewish for Aliyah to Israel?

The answer to this is actually quite astounding. I moved to Israel a month ago for the purpose of joining the IDF in December. To do this I had to go to the Jewish Agency in Tel Aviv to prove that I am Jewish. I brought a letter from a rabbi, and my birth certificate (all other doents parents ketuba, mothers conversions cert. were burned in a house fire) now here is the strange part, the lady who examined the letter did not speak nor read english, but she certified it, kept a copy for her records, and gave me a copy with her certification for me to bring to the Visa department. All of these places have records and I am sure if anything gets called into question they will do in depth research, but I am also sure the amount of Jews coming in who must prove they are Jewish is much too mive for them to investigate on a case by case basis. I hope this helps.