Reading Darril's book and...

got to chapter 9. My head just exploded.

I don't know if I'm just too tired today or what, but while I was only missing 1-2 questions on the previous 8 chapters, I just can't get my head around the encryption / hashing.

Maybe I'm overthinking things, but some of the information makes me wonder what I'm not learning. For instance, page 416's "Remember" box states the the RC algorithms use block ciphers, and the text elsewhere on the page tell you that IDEA and CAST use block ciphers, but nowhere does it tell you what uses stream ciphers (except for RC4 on page 417). Nor why stream ciphers are weaker than block ciphers.

I probably just need to be patient. After all, this chapter did answer some "unanswered" questions I had about public/private keys from an earlier chapter.

Don't get me wrong; I think it's a great book and I'm enjoying it. I think I'm just frustrated that this section isn't coming as easy to me as some others.

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citinerd

Remeber, this test does not disect crypto as much as you might think. I re-read chapter 9 about 4 times. I took notes on what was discussed to get it to sink in. I think that Darril's book covers all the content and objectives.

I used Darril's book and Trancender practice test and did great. Just re-read the hell out of that chapter and you will do fine.

Hypntick

I'm in a similar boat. Missed no more than 1-2 questions on end of chapter tests. Chapter 9 I missed 4.

But I already knew this was gonna give me trouble. Which is why I want nothing to do with security after this.

erpadmin

Hypntick wrote: »

I'm in a similar boat. Missed no more than 1-2 questions on end of chapter tests. Chapter 9 I missed 4. But I already knew this was gonna give me trouble. Which is why I want nothing to do with security after this.

I wasn't scoring many perfects either...especially chapter 9. Chapter 9 has EVERYTHING you need for the real exam though...you do not need to be a cryptographic expert; just feel comfortable enough with cryptography so that you can confidently schedule the exam, pass it, and then post here how right we all were that Darril's book was enough to pass.

sthompson86

I never was intimidated or overwhelmed with the Crypto sections. Yes, there are big words that I have never heard of, but I understood that CompTIA only required me to know just a general overview of each type of Cryptography.

For instance how many bits does the type of cryptography use to encrypt - Is Symmetric or Asymmetric.

Basically nothing major just memorization of facts.

Darrils book is fantastic BTW!

tomahawkeer

Wow, I was considering posting this thread myself, and happened to notice one already here. The crytpo section is the biggest issue I have with the security+ exam atm. Im currently scheduled to take on on December 8th, so ive got time to get my head wrapped around Crypto, but god, its just one of those things i've not used a lot of throughout my career, which makes it a lot of new material, when compared to the rest of the information on the test.

erpadmin

tomahawkeer wrote: »

Wow, I was considering posting this thread myself, and happened to notice one already here. The crytpo section is the biggest issue I have with the security+ exam atm. Im currently scheduled to take on on December 8th, so ive got time to get my head wrapped around Crypto, but god, its just one of those things i've not used a lot of throughout my career, which makes it a lot of new material, when compared to the rest of the information on the test.

1) Close your eyes for a few and take a deep breath.

2) Understand that cryptography on the Security+ exam is not that bad.

As long as you understand chapter 9, you'll be fine. The biggest thing you'll have to worry about is knowing the difference between asymmetric and symmetric algorithms, plus hashing. What helped me out was looking at certificates on web sites (including the ones I created). Once it "clicks", you'll come back with a passed thread.

Trust me, Darril's book is all you need for this exam. I wish I'd have known that before I bought the Transcenders...

rwmidl

I think everyone has problems with the Crypto chapter.

badboyeee

rwmidl wrote: »

I think everyone has problems with the Crypto chapter.

oh oh.. im on chapter 6 and everything going swell so far, but i'm anticipating chapter 9

Hypntick

badboyeee wrote: »

oh oh.. im on chapter 6 and everything going swell so far, but i'm anticipating chapter 9

Yeah chapter 9 takes a bit longer to work through. Most of my end of chapter tests were either 100% or missing 1 question. I hit chapter 9 and missed 5. If you have your A+ and Network+ most of the stuff in the other chapters is covered in some way or another in those two tests. At least that's how it's seemed to me.

badboyeee

Hypntick wrote: »

Yeah chapter 9 takes a bit longer to work through. Most of my end of chapter tests were either 100% or missing 1 question. I hit chapter 9 and missed 5. If you have your A+ and Network+ most of the stuff in the other chapters is covered in some way or another in those two tests. At least that's how it's seemed to me.

Yeah I have my A+ from long time ago, and then my N+ from 3 weeks ago. DG's book been pretty smooth read so far. I did skip the assessment test, just from a quick browse I barely knew any of the answers. I've been getting 1-4 wrong on the chapter practice questions. I do plan to read the book a second time, looks like I may have to read chapter 9 more than that tho.

Just came from your other thread, goodluck on your exam today!

erpadmin

badboyeee wrote: »

Yeah I have my A+ from long time ago, and then my N+ from 3 weeks ago. DG's book been pretty smooth read so far. I did skip the assessment test, just from a quick browse I barely knew any of the answers. I've been getting 1-4 wrong on the chapter practice questions. I do plan to read the book a second time, looks like I may have to read chapter 9 more than that tho.

Just came from your other thread, goodluck on your exam today!

Dude, my A+ and Network+ were from 5 years prior to taking Security+. If you've been scoring that many wrong in the chapter exams (as I was) then you are good. I did not take the assessment test either. I did take the final and I can tell you if you score 80% or better (I scored 90%), then you are ready for the real test! You're going to pass if you study Darril's book well...I promise.

lanrexng2

i am about to read that chapter I have come across some Crypto in about 3 classes in college so I hope it sinks in tonight

we'll see in a few hours

Travler wrote: »

got to chapter 9. My head just exploded.

I don't know if I'm just too tired today or what, but while I was only missing 1-2 questions on the previous 8 chapters, I just can't get my head around the encryption / hashing.

Maybe I'm overthinking things, but some of the information makes me wonder what I'm not learning. For instance, page 416's "Remember" box states the the RC algorithms use block ciphers, and the text elsewhere on the page tell you that IDEA and CAST use block ciphers, but nowhere does it tell you what uses stream ciphers (except for RC4 on page 417). Nor why stream ciphers are weaker than block ciphers.

I probably just need to be patient. After all, this chapter did answer some "unanswered" questions I had about public/private keys from an earlier chapter.

Don't get me wrong; I think it's a great book and I'm enjoying it. I think I'm just frustrated that this section isn't coming as easy to me as some others.

lol Travler

let's take a chill pill

RC2 and RC4 were both developed about the same time in 1987, I guess Mr Ron was experimenting with Stream and Block ciphers

.

RC4 (Stream cipher) was cracked in 1994 and if you research most of the encryption standards later on used Block cipher. RC5 (Block Cipher) standard was adopted in 1994*

From Google Search University

- Stream ciphers are fast but are also weak mostly because the algorithm uses the key twice.

I am personally getting fascinated by Crypto and turns out the head Information Assurance Professor at my school studied under Ron Rivest.

Here is an old Google Tech Talk video with a brief overview enjoy and keep studying

YouTube - Theory and Practice of Cryptography

Don't forget CompTIA is just the what. For the if, when, why and how you can always trust Google Search University

Travler

lanrexng2 wrote: »

RC2 and RC4 were both developed about the same time in 1987, I guess Mr Ron was experimenting with Stream and Block ciphers .

RC4 (Stream cipher) was cracked in 1994 and if you research most of the encryption standards later on used Block cipher. RC5 (Block Cipher) standard was adopted in 1994*

From Google Search University - Stream ciphers are fast but are also weak mostly because the algorithm uses the key twice.

I am personally getting fascinated by Crypto and turns out the head Information Assurance Professor at my school studied under Ron Rivest.

Here is an old Google Tech Talk video with a brief overview enjoy and keep studying YouTube - Theory and Practice of Cryptography

Don't forget CompTIA is just the what. For the if, when, why and how you can always trust Google Search University

Thanks for the info, and the link!

As a followup:
Before reading the book, I failed the assessment test miserably (missed 37 of 7

. Then, each night I'd read a chapter, come back the next night and answer the chapter's questions without any review first (usually missing 1-4; the 4 being chapter 9), then read the next chapter. After the last chapter, I waited a few days and re-did the assessment exam, again without any review first, and missed 12 of 78. So, with no review I think I'm doing fairly well. I'm currently in the process of hitting the book's Remember boxes and the Review sections after each chapter. I'll also hit the problem areas again (Chap.9) then try to simulate the real exam with the 100 question Final exam.

badboyeee

I just got done with reading Chapter 8 during my lunch break. Also did its practice questions (I got 1 wrong, careless mistake, I read the question wrong grrrr). Chapter 9 up next!

bdub

The questions I saw on the exam for cryptography were not very challenging. I wouldn't worry about understanding every last bit of chapter 9.

On a side note heres something fun:
Moserware: A Stick Figure Guide to the Advanced Encryption Standard (AES)