MENU
Cryptographic hashes are often used for message integrity and password storage. It is important to understand the common properties of all cryptographic hashes. What is not true about a hash?
Suggested Answer: B
Get Premium 212-81 Questions
as Interactive Web-Based Practice Test or PDF
Real Exam Format
Detailed Explanations
Instant Access
Get Your Practice Test
Reversible
https://en.wikipedia.org/wiki/Hash_function
Hash functions are not reversible.
Incorrect answers:
Fixed length output and Variable length input. Hash function receive variable length input and produce fixed length output
Few collisions. Every hash function with more inputs than outputs will necessarily have collisions
43 comments · newest first
AL
Alfred
10 months ago
Fixed length output is a must for hashes, right?
CA
Carylon
10 months ago
I thought hashes could be variable length?
LA
Lanie
10 months ago
Hashes should have few collisions, that's true.
LA
Lajuana
11 months ago
Wait, are we sure about the few collisions part? Sounds risky!
SH
Shawna
11 months ago
Definitely not reversible, that's a key property!
SH
Shawnna
11 months ago
I feel like fixed length output is a standard property of hashes, so D should be true too. This is tricky!
SA
Sabrina
11 months ago
I practiced a similar question about hash properties, and I recall that they can take variable length inputs, so C seems correct.
GE
Gerald
12 months ago
I'm not entirely sure, but I think hashes are supposed to be irreversible, which makes option B the right answer for what is not true.
AN
Annalee
12 months ago
I remember that hashes should have few collisions, so I think option A is true.
MO
Mollie
1 year ago
Hmm, I'm a bit stumped. I know cryptographic hashes have some key properties, but I'm not sure which one is not true. I'll have to think this through carefully and eliminate the options that I'm more confident are true.
AS
Ashlyn
1 year ago
I've got a good feeling about this one. Cryptographic hashes are designed to have very few collisions, so that can't be the answer. And they definitely accept variable-length inputs. The only option left is that they are reversible, which is not true. I'm going with that.
BO
Bong
1 year ago
Whoa, I'm a little confused here. I thought cryptographic hashes were supposed to have fixed-length outputs, but one of the options says that's not true. I better double-check my understanding on this.
TI
Tiffiny
1 year ago
Okay, I've got this. Cryptographic hashes are supposed to be one-way, meaning they can't be reversed. So the answer must be that they are reversible, which is not true.
SH
Shawnda
1 year ago
Hmm, this is a tricky one. I know cryptographic hashes have some key properties, but I'm not sure which one is not true. Let me think this through carefully.
TH
Theron
1 year ago
Ooh, B) Reversible? Sounds like a magic trick, not a cryptographic hash. I'll pass on that one.
RE
Reiko
1 year ago
User 3: D) Fixed length output is also a common property of cryptographic hashes.
MI
Miles
1 year ago
User 2: Miles is correct, collisions can happen with hashes.
BL
Blondell
1 year ago
Yeah, a reversible hash defeats the purpose of hashing in the first place.
BL
Blondell
1 year ago
I agree, a reversible hash doesn't sound secure at all.
DA
Dawne
1 year ago
User 1: A) Few collisions is not true about a hash.
LE
Lelia
1 year ago
Haha, B) Reversible? What is this, amateur hour? Hashes are all about that irreversible goodness, baby!
WI
Wilburn
1 year ago
D) Fixed length output
LO
Lorenza
1 year ago
C) Variable length input
MA
Mayra
1 year ago
A) Few collisions
LA
Laine
1 year ago
Yes, B is the correct answer. Cryptographic hashes are not reversible, making them secure for password storage.
DA
Dalene
1 year ago
I agree with Ceola, cryptographic hashes are designed to be one-way functions.
CE
Ceola
1 year ago
I think B is not true because cryptographic hashes are not reversible.
DU
Dudley
1 year ago
Definitely B) Reversible. That's like the opposite of what a hash is supposed to do. Might as well just store the original message!
CH
Chana
1 year ago
That's right, B) Reversible is definitely not a property of a cryptographic hash.
TR
Trinidad
1 year ago
Exactly, B) Reversible defeats the purpose of using a hash for security.
WI
Willard
1 year ago
Agreed, B) Reversible is not true. A hash should not be reversible.
JE
Jenise
1 year ago
D) Fixed length output
VI
Vilma
1 year ago
C) Variable length input
PA
Pamella
1 year ago
B) Reversible
VI
Virgina
1 year ago
A) Few collisions
LO
Lorrine
1 year ago
B) Reversible
HE
Hester
1 year ago
B) Reversible? That's a big no-no for a secure hash! Hashes are supposed to be one-way, not reversible.
JU
Justine
1 year ago
B) Reversible is not true about a hash.
GE
Georgene
1 year ago
Reversible? That's a big no-no for a secure hash! Hashes are supposed to be one-way, not reversible.
FI
Fidelia
1 year ago
D) Fixed length output
SH
Shantell
1 year ago
C) Variable length input
AN
Anissa
1 year ago
B) Reversible
CR
Craig
1 year ago
A) Few collisions