Certified Encryption Specialist Exam Questions And
100% Correct Answers
Cryptography - Answer The science of transforming information so that it is
unintelligible unless one knows a secret.
Caesar Cipher - Answer Simple encryption system which works by changing the letters,
according to their positions in the alphabet, by a fixed number of places further in the
alphabet.
Atbash - Answer Used by Hebrews, cipher that uses reverse alphabet .
ROT13 - Answer Cipher shifting 13 letters in the alphabet
Scytale - Answer A cylinder tool, used to encrypt and decrypt a plaintext message
written around a rod, wrapped by cloth or leather.
Vigenere Cipher - Answer Most common multi-alphabetic cipher.
Symmetric Encryption - Answer Same key is used to Encrypt and Decrypt plaintext.
Also known as Single Key Encryption.
Diffusion - Answer Changes to one letter in plaintext changes multiple characters of the
ciphertext.
Confusion - Answer Makes the relationship between the statistical frequencies of the
ciphertext and the actual key as complex as possible.
,Avalanche - Ans A slight change in the input produces a significant change in output.
Complete Avalanche - Ans A change of one bit of the plaintext changes all bits in the
ciphertext.
Kerckhoffs Principle - Ans The crypto system should be secured if everything about the
system, except the key is publicly known.
Substitution - Ans Replacing some portion of the plaintext with some equivalent portion
of the ciphertext.
Transposition - Solution Block swap of ciphertext.
Binary ADD - Solution Stack two binary numbers; If both are 1 then it's 1, else 0.
Binary OR - Solution Stack two binary numbers; if either is a 1 then it's 1, else 0.
Binary XOR - Answer Follow the binary number and stack them; 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 - Answer Encrypts the information in blocks.
Stream Cipher - Answer Encrypts the information one bit at a time.
DES - Answer Data Encryption Standard
DES (Characteristics) - Answer Made by IBM in 1970's.
64 bit Block Cipher.
56 Bit Key.
, Uses Feistal Cipher.
Feistal Function - Answer 64 Bits split Left and Right, Round function to one side, XORed
with the other side then sides are Transposed or switched.
Then to be continued for a set number of rounds.
Unbalanced Feistal Function - Answer Same as Feistal but the 64 bits are not equally
split.
Skipjack uses the Unbalanced Feistal Function.
3DES-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 - 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 - Answer A process of XORing in an additional key at any time in the
encryption process.
AES - Answer Advanced Encryption Standard
AES -Characteristics- 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.
Based on substitution-permutation matrix.
Blowfish -Characteristics- Answer Capable of Key sizes 32 to 448 bits.
64 bit Block Size.
Bruce Schneier.
100% Correct Answers
Cryptography - Answer The science of transforming information so that it is
unintelligible unless one knows a secret.
Caesar Cipher - Answer Simple encryption system which works by changing the letters,
according to their positions in the alphabet, by a fixed number of places further in the
alphabet.
Atbash - Answer Used by Hebrews, cipher that uses reverse alphabet .
ROT13 - Answer Cipher shifting 13 letters in the alphabet
Scytale - Answer A cylinder tool, used to encrypt and decrypt a plaintext message
written around a rod, wrapped by cloth or leather.
Vigenere Cipher - Answer Most common multi-alphabetic cipher.
Symmetric Encryption - Answer Same key is used to Encrypt and Decrypt plaintext.
Also known as Single Key Encryption.
Diffusion - Answer Changes to one letter in plaintext changes multiple characters of the
ciphertext.
Confusion - Answer Makes the relationship between the statistical frequencies of the
ciphertext and the actual key as complex as possible.
,Avalanche - Ans A slight change in the input produces a significant change in output.
Complete Avalanche - Ans A change of one bit of the plaintext changes all bits in the
ciphertext.
Kerckhoffs Principle - Ans The crypto system should be secured if everything about the
system, except the key is publicly known.
Substitution - Ans Replacing some portion of the plaintext with some equivalent portion
of the ciphertext.
Transposition - Solution Block swap of ciphertext.
Binary ADD - Solution Stack two binary numbers; If both are 1 then it's 1, else 0.
Binary OR - Solution Stack two binary numbers; if either is a 1 then it's 1, else 0.
Binary XOR - Answer Follow the binary number and stack them; 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 - Answer Encrypts the information in blocks.
Stream Cipher - Answer Encrypts the information one bit at a time.
DES - Answer Data Encryption Standard
DES (Characteristics) - Answer Made by IBM in 1970's.
64 bit Block Cipher.
56 Bit Key.
, Uses Feistal Cipher.
Feistal Function - Answer 64 Bits split Left and Right, Round function to one side, XORed
with the other side then sides are Transposed or switched.
Then to be continued for a set number of rounds.
Unbalanced Feistal Function - Answer Same as Feistal but the 64 bits are not equally
split.
Skipjack uses the Unbalanced Feistal Function.
3DES-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 - 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 - Answer A process of XORing in an additional key at any time in the
encryption process.
AES - Answer Advanced Encryption Standard
AES -Characteristics- 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.
Based on substitution-permutation matrix.
Blowfish -Characteristics- Answer Capable of Key sizes 32 to 448 bits.
64 bit Block Size.
Bruce Schneier.
