Certified Encryption Specialist UPDATED
Exam Questions and CORRECT Answers
Cryptography - CORRECT ANSWER - The science of altering communication so that it
cannot be understood without having a key.
Caesar Cipher - CORRECT ANSWER - Simple cipher that uses shifting letters.
Atbash - CORRECT ANSWER - Used by Hebrews, cipher that reverses the alphabet.
ROT13 - CORRECT ANSWER - Cipher that rotate or shifts by 13 letters.
Scytale - CORRECT ANSWER - Cylinder tool used to encrypt and decrypt plaintext using a
cloth or piece of leather wrapped around a rod.
Vigenere Cipher - CORRECT ANSWER - Most common multi-alphabetic cipher.
Symmetric Encryption - CORRECT ANSWER - Same key is used to Encrypt and Decrypt
plaintext.
Also known as Single Key Encryption.
Diffusion - CORRECT ANSWER - Changes to one letter in plaintext changes multiple
characters of the ciphertext.
Confusion - CORRECT ANSWER - Makes the relationship between the statistical
frequencies of the ciphertext and the actual key as complex as possible.
Avalanche - CORRECT ANSWER - A small change in the input yields a large change in the
output.
,Complete Avalanche - CORRECT ANSWER - A change in one bit of the plaintext affecting
all bits in the ciphertext.
Kerckhoffs Principle - CORRECT ANSWER - The crypto system should be secure if
everything about the system, except the key, is publicly known.
Substitution - CORRECT ANSWER - Changing some part of the plaintext for some matching
part of the ciphertext.
Transposition - CORRECT ANSWER - Swapping of blocks of ciphertext.
Binary ADD - CORRECT ANSWER - Stack both binary numbers; If both numbers are 1 then
it's 1, otherwise it's 0.
Binary OR - CORRECT ANSWER - Stack both binary numbers; If either is a 1 then it's 1,
otherwise it's 0.
Binary XOR - CORRECT ANSWER - Stack both binary numbers; If their is a 1 in one
number but not the other then it's a 1, otherwise its 0.
This is reversible.
Block Cipher - CORRECT ANSWER - Encrypts the information in blocks.
Stream Cipher - CORRECT ANSWER - Encrypts the information one bit at a time.
DES - CORRECT ANSWER - Data Encryption Standard
DES (Characteristics) - CORRECT ANSWER - Made by IBM in 1970's.
, 64 bit Block Cipher.
56 Bit Key.
Uses Feistal Cipher.
Feistal Function - CORRECT ANSWER - 64 Bits split Left and Right, Round function to one
side, XORed with the other side then sides are Transposed or switched.
Then continued for a set number of rounds.
Unbalanced Feistal Function - CORRECT ANSWER - Same as Feistal but the 64 bits are not
equally split.
Skipjack uses the Unbalanced Feistal Function.
3DES - CORRECT ANSWER - Uses Data Encryption Standard with a key bundle. Three 56
bit keys are used to encrypt with key 1, decrypt with key 2 and then encrypt with key 3.
DESx - CORRECT ANSWER - Same as Data Encryption Standard but the plaintext is
XORed with the key then encrypted.
Is not more secure since the key space is still the same.
Whitening - CORRECT ANSWER - The process of XORing in an additional key at any time
in the encryption process.
AES - CORRECT ANSWER - Advanced Encryption Standard
AES (Characteristics) - CORRECT ANSWER - Replaced DES in 2001.
Capable of Key sizes 128 bit, 192 bit, and 256 bit.
128 bit Block Size.
Developed by Joan Daemen and Vincent Rimen.
Designated as FIPS 197.
Exam Questions and CORRECT Answers
Cryptography - CORRECT ANSWER - The science of altering communication so that it
cannot be understood without having a key.
Caesar Cipher - CORRECT ANSWER - Simple cipher that uses shifting letters.
Atbash - CORRECT ANSWER - Used by Hebrews, cipher that reverses the alphabet.
ROT13 - CORRECT ANSWER - Cipher that rotate or shifts by 13 letters.
Scytale - CORRECT ANSWER - Cylinder tool used to encrypt and decrypt plaintext using a
cloth or piece of leather wrapped around a rod.
Vigenere Cipher - CORRECT ANSWER - Most common multi-alphabetic cipher.
Symmetric Encryption - CORRECT ANSWER - Same key is used to Encrypt and Decrypt
plaintext.
Also known as Single Key Encryption.
Diffusion - CORRECT ANSWER - Changes to one letter in plaintext changes multiple
characters of the ciphertext.
Confusion - CORRECT ANSWER - Makes the relationship between the statistical
frequencies of the ciphertext and the actual key as complex as possible.
Avalanche - CORRECT ANSWER - A small change in the input yields a large change in the
output.
,Complete Avalanche - CORRECT ANSWER - A change in one bit of the plaintext affecting
all bits in the ciphertext.
Kerckhoffs Principle - CORRECT ANSWER - The crypto system should be secure if
everything about the system, except the key, is publicly known.
Substitution - CORRECT ANSWER - Changing some part of the plaintext for some matching
part of the ciphertext.
Transposition - CORRECT ANSWER - Swapping of blocks of ciphertext.
Binary ADD - CORRECT ANSWER - Stack both binary numbers; If both numbers are 1 then
it's 1, otherwise it's 0.
Binary OR - CORRECT ANSWER - Stack both binary numbers; If either is a 1 then it's 1,
otherwise it's 0.
Binary XOR - CORRECT ANSWER - Stack both binary numbers; If their is a 1 in one
number but not the other then it's a 1, otherwise its 0.
This is reversible.
Block Cipher - CORRECT ANSWER - Encrypts the information in blocks.
Stream Cipher - CORRECT ANSWER - Encrypts the information one bit at a time.
DES - CORRECT ANSWER - Data Encryption Standard
DES (Characteristics) - CORRECT ANSWER - Made by IBM in 1970's.
, 64 bit Block Cipher.
56 Bit Key.
Uses Feistal Cipher.
Feistal Function - CORRECT ANSWER - 64 Bits split Left and Right, Round function to one
side, XORed with the other side then sides are Transposed or switched.
Then continued for a set number of rounds.
Unbalanced Feistal Function - CORRECT ANSWER - Same as Feistal but the 64 bits are not
equally split.
Skipjack uses the Unbalanced Feistal Function.
3DES - CORRECT ANSWER - Uses Data Encryption Standard with a key bundle. Three 56
bit keys are used to encrypt with key 1, decrypt with key 2 and then encrypt with key 3.
DESx - CORRECT ANSWER - Same as Data Encryption Standard but the plaintext is
XORed with the key then encrypted.
Is not more secure since the key space is still the same.
Whitening - CORRECT ANSWER - The process of XORing in an additional key at any time
in the encryption process.
AES - CORRECT ANSWER - Advanced Encryption Standard
AES (Characteristics) - CORRECT ANSWER - Replaced DES in 2001.
Capable of Key sizes 128 bit, 192 bit, and 256 bit.
128 bit Block Size.
Developed by Joan Daemen and Vincent Rimen.
Designated as FIPS 197.
