Interview with MS today: now updated after

[Descartes]

Originally posted by: Kyteland

Originally posted by: Davegod75
#2 = PKI for the bonus?

Public Key Incryption?

Yes, #2 is a parallel to Encryption.

Try public key infrastructure.

 

[StageLeft]

#1 is easy. First I'd weigh 5 balls on one and 3 on the other .If the 3 are lighter 4 more weighings and you can figure it out. If 5 is heavier it needs only 6 more weighings of the 3 to see which one is heavier than half of the 5 lighter balls.

 

[sygyzy]

Read "How do you move Mt. Fuji"

 

[Garet Jax]

#1 - Weigh 3 balls on each side. If they are equal, lighter ball is in the group of two not weighed. One more weighing will determine the lighter one. If they are not equal, take the group of three that rises (the lighter group). From this group, randomly choose two balls and weigh them. If they are equal, lighter ball is the one that wasn't weighed. If they are not equal, then lighter ball is the one that rose during the last weighing.

#2 - Put diamonds in box, lock box with my lock. Send box to recipient, recipient locks with his lock (two locks on the box). He sends back to me, I remove my lock and send back to him. He removes his lock and gets diamonds. Close to PKI.

 

[Ameesh]

Originally posted by: ReelC00L

Originally posted by: Ameesh
the 1st campus interview is pretty easy, if you did well expect to be flown out to redmond for a full loop with 2 groups ie 3-5 interviews spanning 8-10 hours

those are pretty tough. Sounds like you did well on the first rounds which is good but be prepared for the <scary voice> hardest interview you will do as a developer </scary voice>

what position did you apply for? PM, STE,SDET or SDE?

let me know if you have any questions and good luck

Thanks for the insight. I got the feeling from someone else's comment that you worked there. What do you do? Please PM me if you prefer. I put down in order of preference: PM, STE, SDE, SDET (not too sure about the last two). What surprised me was that many of the interviewees that I recognized (about 1/3) were masters students. I didn't see a single undergrad name that I recognized on there besides my own. 1 week until I find out the result and I have another interview on Friday with Raytheon but I expect that one to be more of the typical sort.

for gods sake dont go to raytheon its the shithole of the universe, i worked for them for 6 months in college it was soooooo boring.

 

[StageLeft]

#2 - Put diamonds in box, lock box with my lock. Send box to recipient, recipient locks with his lock (two locks on the box). He sends back to me, I remove my lock and send back to him. He removes his lock and gets diamonds. Close to PKI.

Or, he can simply send you his lock and then you put the diamonds on and his lock on at that time, and that's even closer to PKI. Because you can lock his lock, you just can't unlock it.

 

[Ameesh]

Originally posted by: Skoorb

#2 - Put diamonds in box, lock box with my lock. Send box to recipient, recipient locks with his lock (two locks on the box). He sends back to me, I remove my lock and send back to him. He removes his lock and gets diamonds. Close to PKI.

Or, he can simply send you his lock and then you put the diamonds on and his lock on at that time, and that's even closer to PKI. Because you can lock his lock, you just can't unlock it.

the interviewer will probably respond that joe diamond theif will exchange the recipeients lock with his own while the mail is in transit and then only he will be able to open the lock.

 

[Fiveohhh]

Originally posted by: ReelC00L
Anything shipped in the box must be locked or it will be stolen.

 

[Thraxen]

the interviewer will probably respond that joe diamond theif will exchange the recipeients lock with his own while the mail is in transit and then only he will be able to open the lock.

Nah... he will just say the lock will be stolen since the original problem states that anything shipped in an unlocked box will be stolen.

 

[StageLeft]

Originally posted by: Fiveohhh

Originally posted by: ReelC00L
Anything shipped in the box must be locked or it will be stolen.

So...? Will the box be stolen or the air inside the box? Neither myself nor garret would have the box even shipped itself without a lock on it, let alone diamonds in it without a lock!

 

[StageLeft]

Originally posted by: Thraxen

the interviewer will probably respond that joe diamond theif will exchange the recipeients lock with his own while the mail is in transit and then only he will be able to open the lock.

Nah... he will just say the lock will be stolen since the original problem states that anything shipped in an unlocked box will be stolen.

Yeah but I'm saying the receiver can ship his lock just throw that bitch in a small box and ship it over!

 

[Kyteland]

Originally posted by: Ameesh

Originally posted by: Skoorb

#2 - Put diamonds in box, lock box with my lock. Send box to recipient, recipient locks with his lock (two locks on the box). He sends back to me, I remove my lock and send back to him. He removes his lock and gets diamonds. Close to PKI.

Or, he can simply send you his lock and then you put the diamonds on and his lock on at that time, and that's even closer to PKI. Because you can lock his lock, you just can't unlock it.

the interviewer will probably respond that joe diamond theif will exchange the recipeients lock with his own while the mail is in transit and then only he will be able to open the lock.

What's to stop joe diamond theif from stealing the box enroute and putting his lock on and sending it back to you, pretending to be the original recipient. Then you take your lock off and ship it out again and he has your diamonds.

That bastard!! :Q

 

[moonshinemadness]

Glad it went well!

 

[Turin39789]

Originally posted by: Kyteland

Originally posted by: Ameesh

Originally posted by: Skoorb

#2 - Put diamonds in box, lock box with my lock. Send box to recipient, recipient locks with his lock (two locks on the box). He sends back to me, I remove my lock and send back to him. He removes his lock and gets diamonds. Close to PKI.

Or, he can simply send you his lock and then you put the diamonds on and his lock on at that time, and that's even closer to PKI. Because you can lock his lock, you just can't unlock it.

the interviewer will probably respond that joe diamond theif will exchange the recipeients lock with his own while the mail is in transit and then only he will be able to open the lock.

What's to stop joe diamond theif from stealing the box enroute and putting his lock on and sending it back to you, pretending to be the original recipient. Then you take your lock off and ship it out again and he has your diamonds.

That bastard!! :Q

I say either jsut keep the damn diamonds for yourself, this is too much of a hassle or ship the box with a bomb in it since we know that fscker joe is going to steal the box, once he is out of the picture you can ship the diamonds safely

 

[Alternex]

#2: You have a lock box and need to ship me some diamonds. Anything shipped in the box must be locked or it will be stolen. You have n locks + keys and I have n locks + keys. Any of your keys works on any of your locks and any of my keys work on any of my locks but not each other's. You can ship the box back as many times as you need. How do you get the diamonds to me?
Bonus: relate it to something in computers.

This is not possible. Mallory can freely swap boxes in transit.. plus he can just steal the boxes without the keys while in transit so no one can get the diamonds! You need a trusted arbitrator (Trent) to help with key exchange. And then nothing can prevent the loss of the boxes in transit.. in computer cryptography land you just send the data again until the receipient receives it.. in this case you don't have that luxury. Get an armored truck and deliver it yourself

 

[Ameesh]

http://rfc.sunsite.dk/rfc/rfc2409.html <-- read this

 

[Alternex]

Originally posted by: Ameesh
http://rfc.sunsite.dk/rfc/rfc2409.html <-- read this

Right.. but this assumes you already have each other's public key.. hence the need for a mutually trusted arbitrator (Trent, aka VeriSign)

 

[Ameesh]

Originally posted by: Alternex

Originally posted by: Ameesh
http://rfc.sunsite.dk/rfc/rfc2409.html <-- read this

Right.. but this assumes you already have each other's public key.. hence the need for a mutually trusted arbitrator (Trent, aka VeriSign)

actually it assumes that you have an authentication authority in your system, i.e. if i ask skoorb if he is skoorb he will always respond i am skoorb but if i ask you are you skoorb, you will have to respond no im not.

 

[Alternex]

Originally posted by: Ameesh

Originally posted by: Alternex

Originally posted by: Ameesh
http://rfc.sunsite.dk/rfc/rfc2409.html <-- read this

Right.. but this assumes you already have each other's public key.. hence the need for a mutually trusted arbitrator (Trent, aka VeriSign)

actually it assumes that you have an authentication authority in your system, i.e. if i ask skoorb if he is skoorb he will always respond i am skoorb but if i ask you are you skoorb, you will have to respond no im not.

Well that's your trusted arbitrator. All key exchange mechanisms need some level of trust at the base level. Either you trust an arbitrator or you exchange keys with the receipient face to face.

 

[Garet Jax]

Originally posted by: Alternex

Originally posted by: Ameesh

Originally posted by: Alternex

Originally posted by: Ameesh
http://rfc.sunsite.dk/rfc/rfc2409.html <-- read this

Right.. but this assumes you already have each other's public key.. hence the need for a mutually trusted arbitrator (Trent, aka VeriSign)

actually it assumes that you have an authentication authority in your system, i.e. if i ask skoorb if he is skoorb he will always respond i am skoorb but if i ask you are you skoorb, you will have to respond no im not.

Well that's your trusted arbitrator. All key exchange mechanisms need some level of trust at the base level. Either you trust an arbitrator or you exchange keys with the receipient face to face.

Right, but if you are choosing an arbitrator, with all the good choices, why on earth would it be Skoorb.

 

[Rilescat]

so how did you interpret the questions? How did you answer them?

 

[Alternex]

Originally posted by: Garet Jax

Originally posted by: Alternex

Originally posted by: Ameesh

Originally posted by: Alternex

Originally posted by: Ameesh
http://rfc.sunsite.dk/rfc/rfc2409.html <-- read this

Right.. but this assumes you already have each other's public key.. hence the need for a mutually trusted arbitrator (Trent, aka VeriSign)

actually it assumes that you have an authentication authority in your system, i.e. if i ask skoorb if he is skoorb he will always respond i am skoorb but if i ask you are you skoorb, you will have to respond no im not.

Well that's your trusted arbitrator. All key exchange mechanisms need some level of trust at the base level. Either you trust an arbitrator or you exchange keys with the receipient face to face.

Right, but if you are choosing an arbitrator, with all the good choices, why on earth would it be Skoorb.

Why? you don't trust Skoorb?
Anyways I believe Ameesh meant Skoorb is a user in the system. The authentication authority is a system that each user trusts to validate the identity of people within the network

 

[Reel]

Originally posted by: ReelC00L
#1: You have 8 balls, 1 is lighter than the others but not visually obvious which. You have a balance scale and are only allowed to weigh them twice. How do you figure which is the lighter one?

#2: You have a lock box and need to ship me some diamonds. Anything shipped in the box must be locked or it will be stolen. You have n locks + keys and I have n locks + keys. Any of your keys works on any of your locks and any of my keys work on any of my locks but not each other's. You can ship the box back as many times as you need. How do you get the diamonds to me?
Bonus: relate it to something in computers.

#3: Define the objects (as in OO Programming) that you would need to create the game pac-man.

#1: my answer has been said here. 3 vs 3, go on from there. I figured this one out pretty quickly.

#2: my first answer was not the best answer but it impressed the interviewer because nobody had ever given that answer before. I had suggested something similar as said above where the receiver sends me a lock locked to the outside of the box but not locking the key in. It wasn't the best answer because security was compromised by sharing the key. Then, I rethought it and gave a better answer. Then he pointed out that it would be wasteful on "bandwidth" to send the diamonds 3 times. The best answer that I came up with was only sending the diamonds once and not sharing a key. I can't remember the details of the solution right now. I'd have to think about it but that should be enough to get some of the guys in the forum thinking of the answer.

#3: We really didn't spend a lot of time on this. I just suggested a few objects: Pac-man, ghost, dot, cells. Those were my framework for the pac-man game. He said we could have spent half an hour on this problem on its own but since time was limited, we would stop there.

 

[Reel]

Originally posted by: Ameesh

Originally posted by: ReelC00L

Originally posted by: Ameesh
the 1st campus interview is pretty easy, if you did well expect to be flown out to redmond for a full loop with 2 groups ie 3-5 interviews spanning 8-10 hours

those are pretty tough. Sounds like you did well on the first rounds which is good but be prepared for the <scary voice> hardest interview you will do as a developer </scary voice>

what position did you apply for? PM, STE,SDET or SDE?

let me know if you have any questions and good luck

Thanks for the insight. I got the feeling from someone else's comment that you worked there. What do you do? Please PM me if you prefer. I put down in order of preference: PM, STE, SDE, SDET (not too sure about the last two). What surprised me was that many of the interviewees that I recognized (about 1/3) were masters students. I didn't see a single undergrad name that I recognized on there besides my own. 1 week until I find out the result and I have another interview on Friday with Raytheon but I expect that one to be more of the typical sort.

for gods sake dont go to raytheon its the shithole of the universe, i worked for them for 6 months in college it was soooooo boring.

Which division of Raytheon were you working for? I am doing a project now for the Secure Networks division and some of that stuff seems cool. Of course, Microsoft seems to have them beat hands-down on the environment category.

 

[m2kewl]

glad you had a good interview!

IMO, working for MS will be a good experience, even for all the bad rap it gets in the public's eyes...as i've learned a lot when i spent time there. if they fly you out to see the campus - i'm sure you'll enjoy it. it was awesome when i saw it the first time ('97).

good luck!! hope you get an offer.