Free Eccouncil 212-81 Exam Actual Questions

The questions for 212-81 were last updated On Nov 16, 2024

Question No. 1

Which one of the following attempts to hide data in plain view?

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Correct Answer: C

Steganography

https://en.wikipedia.org/wiki/Steganography

Steganography is the practice of concealing a file, message, image, or video within another file, message, image, or video. The word steganography comes from Greek steganographia, which combines the words stegans , meaning 'covered or concealed', and -graphia meaning 'writing'.


Question No. 2

Which algorithm was U. S. Patent 5,231,668, filed on july 26, 1991, attributed to David W. Kravitz, and adopted by the U. S. government in 1993 with FIPS 186?

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Correct Answer: A

DSA

https://en.wikipedia.org/wiki/Digital_Signature_Algorithm

DSA is covered by U.S. Patent 5,231,668 , filed July 26, 1991 and now expired, and attributed to David W. Kravitz, a former NSA employee. This patent was given to 'The United States of America as represented by the Secretary of Commerce, Washington, D.C.', and NIST has made this patent available worldwide royalty-free. Claus P. Schnorr claims that his U.S. Patent 4,995,082 (also now expired) covered DSA; this claim is disputed.


Question No. 3

Ahlen is using a set of pre-calculated hashes to attempt to derive the passwords from a Windows SAM file. What is a set of pre-calculated hashes used to derive a hashed password called?

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Correct Answer: B

Rainbow table

https://en.wikipedia.org/wiki/Rainbow_table

A rainbow table is a precomputed table for caching the output of cryptographic hash functions, usually for cracking password hashes. Tables are usually used in recovering a key derivation function (or credit card numbers, etc.) up to a certain length consisting of a limited set of characters. It is a practical example of a space--time tradeoff, using less computer processing time and more storage than a brute-force attack which calculates a hash on every attempt, but more processing time and less storage than a simple key derivation function with one entry per hash. Use of a key derivation that employs a salt makes this attack infeasible.


Question No. 4

The most widely used asymmetric encryption algorithm is what?

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Correct Answer: C

RSA

The RSA encryption algorithm is one of the most widely used public key encryption algorithms that have ever been invented. It was created by the three scientists Ronald Rivest, Adi Shamir, and Leonard Adleman in 1977, and today it is increasingly being used in the network area.

Incorrect answers:

Caesar Cipher - 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.

Vigenere - Multi alphabet cipher Invented by Giovan Battista Bellaso in middle 1553. Vigenere created a stronger version of the cipher. Combining/Weaving Caesar cipher. Not cracked until late 1800s. Widely used from 16th century to early 20th century. It is a cipher square with A to Z across all the columns and rows. You then use a keyword to encrypt the message

DES - The Data Encryption Standard is a symmetric-key algorithm for the encryption of digital data.


Question No. 5

A 160-bit hash algorithm developed by Hans Dobbertin, Antoon Bosselaers, and Bart Preneel for which there are 128, 256 and 320-bit versions is called what?

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Correct Answer: D

RIPEMD

https://en.wikipedia.org/wiki/RIPEMD

RIPEMD (RIPE Message Digest) is a family of cryptographic hash functions developed in 1992 (the original RIPEMD) and 1996 (other variants). There are five functions in the family: RIPEMD, RIPEMD-128, RIPEMD-160, RIPEMD-256, and RIPEMD-320, of which RIPEMD-160 is the most common.

The original RIPEMD, as well as RIPEMD-128, is not considered secure because 128-bit result is too small and also (for the original RIPEMD) because of design weaknesses. The 256- and 320-bit versions of RIPEMD provide the same level of security as RIPEMD-128 and RIPEMD-160, respectively; they are designed for applications where the security level is sufficient but longer hash result is necessary.