Which of the following is the correct order of operations inside the DES round function (F function)?

XOR with subkey, expansion, P-box permutation, S-box substitution

Expansion, XOR with subkey, S-box substitution, P-box permutation

S-box substitution, expansion, XOR with subkey, P-box permutation

P-box permutation, expansion, XOR with subkey, S-box substitution

Which statement about the number of rounds in a Feistel network is generally true?

Fewer rounds always make the cipher faster without reducing security

The number of rounds is determined by the block size

The number of rounds is always fixed at 16

More rounds generally increase security but also increase computational cost

An organization is migrating from DES to 3DES for legacy data encryption. They have a requirement to maintain backward compatibility with systems that only support single DES. They plan to use 3DES in EDE mode. Which keying option allows them to decrypt data encrypted with single DES using the same 3DES implementation?

Use three independent keys (K1, K2, K3 all different).

Use three identical keys (K1 = K2 = K3).

Use two keys, with K1 = K3 and K2 different.

EC-CouncilCertified Encryption Specialist

Domain 2Objective 1

Feistel Networks, DES, 3DES, and AES ECES Practice Questions (Page 8)

Part of the Symmetric Cryptography and Hashing domain, which makes up ~17% of our current practice bank. EC-Council does not publish an official question count, but from its 120-minute exam (~50–80 total, ~9–14 in this domain), expect 3–5 from this objective — we provide 51 practice questions to prepare you well beyond it. (estimate)

51questions here

11free pages

12concepts

Questions 36–40

36foundation · easy
In AES key expansion, what is the term for the operation that rotates a word and applies the S-box to each byte?
Select an answer first
37application · medium
A company is evaluating ciphers for a new product and has a requirement that the cipher must be resistant to known cryptanalytic attacks and be efficient in both software and hardware. They are considering DES, 3DES, and AES. Which cipher should they select?
Select an answer first
38foundation · easy
Which of the following is the correct order of operations inside the DES round function (F function)?
Select an answer first
39foundation · easy
Which statement about the number of rounds in a Feistel network is generally true?
Select an answer first
40application · medium
An organization is migrating from DES to 3DES for legacy data encryption. They have a requirement to maintain backward compatibility with systems that only support single DES. They plan to use 3DES in EDE mode. Which keying option allows them to decrypt data encrypted with single DES using the same 3DES implementation?
Select an answer first

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Feistel Networks, DES, 3DES, and AES ECES Practice Questions (Page 8)

Questions 36–40

In AES key expansion, what is the term for the operation that rotates a word and applies the S-box to each byte?

A company is evaluating ciphers for a new product and has a requirement that the cipher must be resistant to known cryptanalytic attacks and be efficient in both software and hardware. They are considering DES, 3DES, and AES. Which cipher should they select?

Which of the following is the correct order of operations inside the DES round function (F function)?

Which statement about the number of rounds in a Feistel network is generally true?

Keep studying — Symmetric Cryptography and Hashing