212-81 Exam Questions and Answers | Exam-Dumps (Page: 2)

QUESTION: 6

What is a salt?

Key whitening
Random bits intermixed with a symmetric cipher to increase randomness and make it more secure
Key rotation
Random bits intermixed with a hash to increase randomness and reduce collisions

Answer(s): D

Explanation:

Random bits intermixed with a hash to increase randomness and reduce collisions https://en.wikipedia.org/wiki/Salt_(cryptography)
Salt is random data that is used as an additional input to a one-way function that hashes data, a password or passphrase. Salts are used to safeguard passwords in storage. Historically a password was stored in plaintext on a system, but over time additional safeguards were developed to protect a user's password against being read from the system. A salt is one of those methods.

Incorrect answers:
Key whitening - a technique used to increase the security of block ciphers. It consists of steps that combine the data with portions of the key (most commonly using a simple XOR) before the first round and after the last round of encryption.
Key rotation - is when you retire an encryption key and replace that old key by generating a new cryptographic key. Rotating keys on a regular basis help meet industry standards and cryptographic best practices.
Random bits intermixed with a symmetric cipher to increase randomness and make it more secure – Initialization Vector (IV)

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QUESTION: 7

Which of the following was a multi alphabet cipher widely used from the 16th century to the early 20th century?

Atbash
Caesar
Scytale
Vigenere

Answer(s): D

Explanation:

Vigenere https://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher
The Vigenère cipher is a method of encrypting alphabetic text by using a series of interwoven Caesar ciphers, based on the letters of a keyword. It employs a form of polyalphabetic substitution.
First described by Giovan Battista Bellaso in 1553, the cipher is easy to understand and implement, but it resisted all attempts to break it until 1863, three centuries later. This earned it the description le chiffre indéchiffrable (French for 'the indecipherable cipher'). Many people have tried to implement encryption schemes that are essentially Vigenère ciphers. In 1863, Friedrich Kasiski was the first to publish a general method of deciphering Vigenère ciphers.

Incorrect answers:
Caesar - Monoalphabetic cipher where letters are shifted one or more letters in either direction. The method is named after Julius Caesar, who used it in his private correspondence.
Atbash - Single substitution monoalphabetic cipher that substitutes each letter with its reverse (a and z, b and y, etc).
Scytale - Transposition cipher. A staff with papyrus or letter wrapped around it so edges would line up. There would be a stream of characters which would show you your message. When unwound it would be a random string of characters. Would need an identical size staff on other end for other individuals to decode message.

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QUESTION: 8

A symmetric Stream Cipher published by the German engineering firm Seimans in 1993. A software based stream cipher that uses a Lagged Fibonacci generator along with concepts borrowed from shrinking generator ciphers.

DESX
FISH
Twofish
IDEA

Answer(s): B

Explanation:

FISH https://en.wikipedia.org/wiki/FISH_(cipher)
The FISH (FIbonacci SHrinking) stream cipher is a fast software based stream cipher using Lagged Fibonacci generators, plus a concept from the shrinking generator cipher. It was published by Siemens in 1993. FISH is quite fast in software and has a huge key length. However, in the same paper where he proposed Pike, Ross Anderson showed that FISH can be broken with just a few thousand bits of known plaintext.

Incorrect answers:
Twofish - symmetric algorithm. Designed by Bruce Schneier, John Kelsey, Doug Whiting, David Wagner, Chris Hall, and Niels Ferguson. Uses a block size of 128 bits and key sizes of 128, 192, or 256 bits. It is a Feistel cipher.
IDEA - symmetric algorithm. Designed by James Massey and Xuejia Lai. Operates on 64 bit blocks and has a 128 bit key. Consists of 8 identical transformations each round and an output transformation.
DESX - symmetric algorithm. 64 bit key is appended to data, XOR it, and then apply the DES algorithm.

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QUESTION: 9

What advantage do symmetric algorithms have over asymmetric algorithms

It is easier to implement them in software
They are more secure
They are faster
D It is easier to exchange keys

Answer(s): C

Explanation:

They are faster Symmetric key encryption is much faster than asymmetric key encryption, because both the sender and the recipient of a message to use the same secret key.

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QUESTION: 10

Which one of the following is an example of a symmetric key algorithm?

ECC
Diffie-Hellman
RSA
Rijndael

Answer(s): D

Explanation:

Rijndael https://en.wikipedia.org/wiki/Advanced_Encryption_Standard
The Advanced Encryption Standard (AES), also known by its original name Rijndael. The algorithm described by AES is a symmetric-key algorithm, meaning the same key is used for both encrypting and decrypting the data.

Incorrect answers:
ECC - Elliptic-curve cryptography is an approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields. ECC allows smaller keys compared to non-EC cryptography (based on plain Galois fields) to provide equivalent security.
Diffie–Hellman - key exchange is a method of securely exchanging cryptographic keys over a public channel and was one of the first public-key protocols as conceived by Ralph Merkle and named after Whitfield Diffie and Martin Hellman.
RSA - Rivest–Shamir–Adleman is a public-key cryptosystem that is widely used for secure data transmission. It is also one of the oldest. The acronym RSA comes from the surnames of Ron Rivest, Adi Shamir, and Leonard Adleman, who publicly described the algorithm in 1977.

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EC-Council 212-81 Exam (page: 2) EC-Council Certified Encryption Specialist Updated on: 25-Dec-2025

QUESTION: 6

Explanation:

QUESTION: 7

Explanation:

QUESTION: 8

Explanation:

QUESTION: 9

Explanation:

QUESTION: 10

Explanation:

EC-Council 212-81 Exam (page: 2)
EC-Council Certified Encryption Specialist
Updated on: 25-Dec-2025