some other indications of the authenticity of the torah.
the laws of shmita (Parsha Behar) (every seven years everyone in israel must stop working the land for the whole year. God promises to provide a bumper crop prior to the Shmita year to sustain the Jewish people). furthermore, in the yovel year this would be two consecutive years where noone planted anything. What human in his right mind would fabricate such a claim and risk mass starvation? (if this were agricultural reasons, it would not be necessary to stop all the land simultaneously)
3 times a year, every year, during the temple era, all Jewish males are commanded to leave their homes and go to Jerusalem for the festivals. God promised: "Nobody will desire your land while you are going up to see the face of the Lord your God three times in the year." (Ex 34:24) Who else could make such a claim but God? No human being in his right mind would enact such a law, leaving his army vulnerable to being encircled and easily defeated. Turns out it proved true that no foreign nation ever came up to take the land of the Jews during their festivals prior to the destruction of Jerusalem 400+ years later.
Kosher. The torah informs us that there is only one animal that has split hooves and does not chew its cud - the pig. Who else but God could claim this? (see this link for more on this: http://www.aish.com/tp/b/lp/48944171.html )
"all fish with scales have moving fins" - who else but God can claim this. (see above link). (some invoke the "sea snake" or "sea eel" as a "refutation" but these scales are embedded in the skin unlike normal fish which are armor-like and come off without peeling off the skin. the hebrew word for scales "kaskasim" is the same as for armor. see: this or this)
The torah's prophecies of the return of the Jews to Israel. (can a nation exiled from its homeland and splintered into a dozen minor ethnic groups for 2,000 years, have the ability and resolve to return en masse to their homeland and become a universally recognized world power?)
Miraculous victories of the israeli army in the early wars (see for example: http://www.chabad.org/multimedia/timeline_cdo/aid/525341/jewish/Introduction.htm or http://www.benmelech.org/z-def/english/israel-bailey.htm) Even Ben Gurion who was a secular Jew is quoted as saying: "In Israel, in order to be a realist you must believe in miracles".
The Tzadikim - those who have had the merit and opportunity of meeting with the Tzadikim (righteous sages) of the generation know that even today, we can find shadows of "prophecy".
the infinite wisdom/depth of the Torah, which is evident to all who study it in depth.
Jews don't go around trying to convert nonjews. on the contrary, they try to discourage potential converts, that it will be too much for them to take on. This is due to the confidence in the timeless truths of Judaism. Those who have a bad product must constantly advertise to lure more suckers. Those who have a good product can rely on word of mouth.
Two more points brought by Rabbi Yaakov Emden (200 years ago, quoted in Masoret Yisrael edition of Chovos Halevavos end of gate 10):
The sign of the truth of these things are from two faithful, visible,
One, our situation and survival in this long exile, which the Creator
fulfilled His promise: "But despite all this, while they are in the
land of their enemies, I will not despise them nor will I reject them
to annihilate them, thereby breaking My covenant that is with them,
for I am the L-ord their G-d" (Vayikra 26:44)...
Two, the matter of our land, because from the day we went out of it,
no nation was able to dwell in it, it was like a woman who's husband
went on a faraway trip, and she waits for him, and the verse "I will
make the Land desolate, so that it will become desolate [also] of your
enemies who live in it" (Vayikra 26:32), tells us it is guarded for
us...all this are clear signs that our hope is not lost and G-d's love
has not left us, and on this eternal love is based Shir Hashirim, and
just like G-d loves us a strong love, "Torrents of water are not able
to extinguish the love" (Shir Hashirim 8:7), so too it is our duty to
show our powerful and complete love, like "As water reflects a face
back to a face, so one's heart is reflected back to him by another"
Mishlei 27:19) END QUOTE (and our survival, despite that we don't try
to convert nonjews, and even discourage them from converting to