Security Engineer Interview Questions | Glassdoor

# Security Engineer Interview Questions

"When hiring a security engineer, employers want to make sure they select candidates who have the technical knowledge of information security software and hardware to ensure their data will be kept safe in the event of a disaster, whether it be an earthquake or a hacker attack. Before attending an interview for this position, prepare to answer a lot of technical questions that will determine the extent of your understanding of information security systems and how they can be used to protect important data."

## Top Interview Questions

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### Security Engineer at Dimension Data was asked...

Aug 23, 2012

Aug 31, 2009
 Write a function that can determine if an input number is a power of 2.4 AnswersMultiple answers. Powers of 2 only have a single 1's bit, rest will be 0's. Use that fact. X (LOGICAL AND) (X - 1) = 0 i.f.f. is a power of 2.Indeed, it is as the previous poster stated. Quite simple -- my initial thought would have been repeated division by 2 looking for a remainder, but that is much heavier lifting. int is_power_of_2 (int val) { if (!(val & val -1)) { return 1; // val is a power of 2 } else { return 0; } }Sure, but every number is a power of 2, or a sum of powers of 2. For example, 16 is (2^4), and 33 is (2^5 + 2^0). If we want to just see if it is divisible, like Brian mentions, well, modulus operator works fine, but I don't think that is entirely the jist of the question. (X % 2) = 0 => divisible by 2, but not necessarily a power of 2, but in stead a sum of powers of 2.Show More ResponsesI like the idea of the `val & (val - 1)`, but it only works for positive integer powers of two. The internal representation of floats ( 2 ^ -3, for example) does not give you a sensible answer when using bitwise and. What you might note is that `log_2(n)` will be an integer if n is a power of 2. In python you can just do this: ```import math def is_power_of_2(n:int) -> bool: return math.log2(n).is_integer()``` Also, even if we're limiting values to nonnegative powers of 2, the log_2 method is fast: ```import math val = 2**4096 - 1 def is_power_of_2_log(n:int) -> bool: return math.log2(val).is_integer() def is_power_of_2_and(n:int) -> bool: return val & (val - 1) == 0 %%timeit is_power_of_2_log(val) # 468 ns ± 32.1 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each) %%timeit is_power_of_2_and(val) # 766 ns ± 12.6 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)```

### Network Security Engineer at Ascend One was asked...

Feb 5, 2010
 How many bits do you need for a subnet size.3 AnswersNeed to know subnetting off top of your head.If number of addreses required in a subnet is "N" , then you need 2 more (network and bcst addreses) in addition to "N". So "N+2" is rounded of to Next 2 to the power . For e.g if we need 64 addresses in a subnet then , 66 rounded to next 2 to the power is is 2**7 ie 128. so number of bits required is 7.The minimum addresses needed is 2 bits for 4 addresses 2^(# of addresses) = 2^2 which used for pint to point links. Max addresses can go as much as class A IP address /8 so for maximum bits is 32-8 = 24 bit

Apr 6, 2010
 Describe the differences between symmetric and asymmetric encryption, and scenarios where one is more appropriate then the other. 1 AnswerNot that difficult if you understand symmetric (private key) vs. asymmetric encryption (public key).

### Network Security Engineer at NetCraftsmen was asked...

Mar 28, 2019
 They were standard questions. They want to see if you are a "cultural" fit. 1 AnswerThis company only gives monthly paychecks. Based on that I declined the position. They will not volunteer this info upfront so don't forget to ask

### Identity Security Engineer at Verizon was asked...

Jun 10, 2013
 How would you handle theoretical situation X.1 AnswerThe question had some nuances, and I tried to be as comprehensive as I could be.

### Senior Cyber Security Engineer at Corporate Risk Solutions (Kansas) was asked...

Apr 25, 2013
 They are so rigid in their interview process that I beleive they overlook talent and are focused on people passing Dr. Mercer's tests2 Answersthree of the people I interviewed with were somewhat disgruntled with the company... overworked.At the end of a 3 hour interview that went perfectly, I was told I'd meet the president of the company. Prez came in and said, "I have 5 minutes." He showed me a bad photocopy of the company's core values... status quo. I said, Yes! I agree. He asked me, "The client is always right. True or false?" I said, "Well, the short answer is 'yes, of course! But for the past decades there's a much larger understanding of customer relationships... and it involves developing a partnership and strong supply chain" . They never called me to inform me of the interview result. I reached out the the company director who never took or returned my calls. No wonder that outfit had a non-stop search for production supervisors and process engineers. The company will be gone in a few years.

Aug 31, 2009