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Comment by Animus7 | Hacker News Reader

You've been a cloud admin for over five years and working with Linux for over 20, but you don't know the difference between symmetric and asymmetric encryption?

I'm as arrogant as the worst of them, but this sounds borderline ridiculous.

That said, I'm looking forward to see how you're looking to change this.

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What exactly would require a Linux sysadmin to be able to articulate the differences between symmetric and asymmetric encryption? Some probably could, but I'd guess most couldn't give you more than a basic one liner.

As long as they have a basic understanding of how SSH, GnuPG, and SSL function and a thorough understanding of how to use them that's probably the extent of the cryptographic expertise required.

Just because it's not required to do the job doesn't mean a curious sysadmin shouldn't know the difference. The difference between symmetric and asymmetric encryption is a pretty basic part of cryptography and if you read about cryptography at all you should know it. I think it shows a lack of interest to not know more than the minimum required to do your job.

Well maybe they were more curious about filesystems and wrote their own? Or they know all about event-based programming but you didn't ask about that because you don't know anything about it?

I think it's wise to avoid "grading" on specific technical questions about things that aren't actually required for the position.

That doesn't mean you shouldn't look for bonus knowledge, but I don't think it's good to be too specific about what it is.

Well, I asked the interviewer if by asymmetric he meant something like PKI, and all I got was a frown. And I was like symmetric encryption is just normal. I think I was more caught off guard, as well as just not thinking much about it. I got all the PAM questions right if that helps. Probably doesn't. I feel genuinely humiliated by the whole situation.

Seriously in the back of my head I heard my Father's voice: "You done fucked up good, boy"

EDIT FOR FATHER QUOTE

The difference is rather simple. (Although I have a feeling that tpatcek will tell me I am wrong on some count)

Asymmetric encryption has two parts, a private key and a public key. One encrypts data with a public key and then the only key that can decrypt it is the private key. The private key, as the name suggests, has to stay private and is a secret, whereas your public key you can hand out as you please.

In symmetric encryption you have a single key, it is used to both encrypt and decrypt the data, and thus if that single key were to fall into the wrong hands that person could then decrypt the data, whereas with a public key that is not the case.

This is a very simplified overview of the differences.

It sounds more like the role was for a senior admin or architect rather than a line admin. I wouldn't beat yourself up too much about it... unless you thought you were a senior admin. Those guys do have to know and understand the nooks and crannies as well as the general processes.

It'd be hard to have worked with Linux for over 20 years at this point since the first public Linux release happened just under 20 years ago (September 1991).

And even in the post, there are more factual errors... Ctrl+D doesn't ask a program to quit. How can you use Linux for 10+ years and not know why kill -9 is "force" and what the difference is from normal kill?

My bad, my math is sucking today.

My brain thought "hm, 1999, now it's 2011, so add 10 to the 1900's to get 2000's, then add 10 more to get 2010's => 20 years".

I always find it interesting to post-mortem my logical blunders.

But sadly, the point stands regardless.

it's just asymmetric math :)

I said a very amateur enthusiast since 1999, which is closer to 10 years. And the Ctrl-D is what I said in my interview I apologize if it is not factual. Looking it up it appears to be end of file, is this correct, I will change my post to reflect this if so.

Yes, Ctrl + D sends an EOF to a program getting input from the console, this can be used to notify mail(1) that you are done typing your message and that it should send the message now.

That's a little harsh.

If he understands how PKI works. If he understands that people share a public key which is in turn paired with a private key. And if he understands that said private key is the only key capable of decrypting messages that were encrypted using the public key, that should be fine.

If he knew that much, he'd probably be able to reason out what 'symmetric' vs 'asymmetric' meant, if given enough time.

Is knowing the exact terms better? Yes.

Is it shameful to understand the concept pretty well without knowing every bit of terminology used to describe it? I'd say no.

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