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1.1 Cryptographic Concepts and Techniques
Fichas del conjunto (69)
- 1What is key stretchingEssentially key strengthening. It makes a weaker key stronger by sending it through another algorithm.
- 2What is hashingRunning data through a cryptographic function to produce a one-way message digest.
- 3Message Digest (MD) 2 Characteristics- Widely used by slow
- 128 Bit Hash Value
- 18 Rounds of Computations - 4Message Digest (MD) 4 Characteristics- 128 Bit Hash Value
- 3 Rounds of Computations - 5Message Digest (MD) 5 Characteristics- Should not be used for SSL
- Should not be used for Digital Signatures
- 128 Bit Hash Value
- 4 Rounds of Computations - 6Message Digest (MD) 6- Variable Hash
- Variable Rounds of Computations - 7How many Secure Hash Algorithm (SHA) versions are there?3 Total
- SHA-0/1
- SHA-2
- SHA-3 - 8SHA-0/1 Characteristics- 160 Bit Hash
- 80 Rounds of Computations
- 512 Bit Blocks - 9SHA-2 Family CharacteristicsA family of hash functions. There are 6 different variations to this version.
- 10SHA-224 Characteristics- 224 Bit Hash
- 64 Rounds of Computation
- 512 Bit Blocks - 11SHA-256 Characteristics- 256 Bit Hash
- 64 Rounds of Computation
- 512 Bit Blocks - 12SHA-384 Characteristics- 384 Bit Hash
- 80 Rounds of Computation
- 1024 Bit Blocks - 13SHA-512 Characteristics- 512 Bit Hash
- 80 Rounds of Computation
- 1024 Bit Blocks - 14SHA-512/224 Characteristics- 224 Bit Hash
- 80 Rounds of Computation
- 1024 Bit Blocks
- 512 is the internal state size - 15SHA-512/256 Characteristics- 256 Bit Hash
- 80 Rounds of Computation
- 1024 Bit Blocks
- 512 is the internal state size - 16DES Characteristics- Name: Digital Encryption Standard
- Cipher Type: Block
Key Size: 64 Bits (56 effective)
Rounds: 16
Block Size: 64 bits - 173DES Characteristics- Name: Triple DES (3DES)
- Cipher Type: Block
Key Size: 56, 112 or 168 bits
Rounds: 48
Block Size: 64 bits - 18AES Characteristics- Name: Advanced Encryption Standard
- Cipher Type: Block
Key Size: 128, 192 or 256 bits
Rounds: 10, 12 or 14
Block Size: 128 bits - 19IDEA Characteristics- Name: International Data Encryption Algorithm
- Cipher Type: Block
Key Size: 128 bits
Rounds: 8
Block Size: 64 bits - 20Skipjack Characteristics- Name: Skipjack
- Cipher Type: Block
Key Size: 80 bits
Rounds: 32
Block Size: 64 bits - 21Blowfish Characteristics- Name: Blowfish
- Cipher Type: Block
Key Size: 32 to 448 bits
Rounds: 16
Block Size: 64 bits - 22Twofish Characteristics- Name: Twofish
- Cipher Type: Block
Key Size: 128, 192 or 256 bits
Rounds: 16
Block Size: 128 bits - 23RC4 Characteristics- Name: RC4
- Cipher Type: Stream
Key Size: 40 to 2048 bits
Rounds: Up to 265
Block Size: N/A - 24RC5 Characteristics- Name: RC5
- Cipher Type: Block
Key Size: Up to 2048 bits
Rounds: Up to 255
Block Size: 32, 64 or 128 bits - 25RC6 Characteristics- Name: RC6
- Cipher Type: Block
Key Size: Up to 2048 bits
Rounds: Up to 255
Block Size: 32, 64 or 128 bits
- Faster than RC5 - 26What is an asymmetric algorithm?A dual-key or public-key crypto. It uses a public and a private key. Public key is known by all and private key is known by owner.
- 27What does an asymmetric algorithm provide?Confidentiality, integrity, authentication and non-repudiation
- 28What are some asymmetric algorithms?Diffie-Hellman, RSA, El Gamal, ECC, Knapsack and Zero Knowledge Proof
- 29What is entropy?Randomness collected by an application that is used in cryptography requiring random data.
- 30What is diffusion?The process of changing the location of the plain text within cipher text.
- 31What is confusion?The process of changing a key value during each round of encryption. Most often by substitution,
- 32What is non-repudiation?Proof of the origin of data.
- 33What is confidentiality?Ensures the data cannot be read except by the valid recipient.
- 34What is integrity?Allowing valid recipients to verify data has not been altered.
- 35What is a wildcard certificate?A certificate that can be used by multiple sub-domains of a domain.
- 36What is OCSP and how does it work?OCSP - Online Certificate Status Protocol
It obtains the revocation status of an X.509 certificate via serial number. Accesses CRL on the CA. - 37What is the CRL and how does it work?CRL - Certification Revocation List
A list of certificates that the CA has revoked. - 38What is an advantage of a stream ciphers?- Lower error of propagation
- Generally used more in hardware
- Same key for decryption and encryption
- Cheaper to implement
- Employ only confusion, not confusion - 39What is an advantage of a block cipher?- Easier to implement
- Less susceptible to security issues
- Used in more software
- Employ both confusion and diffusion - 40What are the 5 modes of DES?- Electronic Code Book (ECB)
- Cipher Block Chaining (CBC)
- Cipher Feedback (CFB)
- Output Feedback (OFB)
- Counter Mode (CTR) - 41What is ECB?- Electronic Code Book
- Uses 64 bit blocks that can be padded.
- Vulnerable, encrypted with same key - 42What is CBC?- Cipher Block Chaining
- 64 bit blocks which are chained.
- Encrypted cipher text block is applied to next block - 43What is CFB?- Cipher Feedback
- 8 bit blocks and uses stream/block cipher
- 8 bit block is fed into next block DES algorithm.
- Do not use for VOX/Video - 44What is OFB?- Output Feedback
- 8 bit blocks and uses stream/block cipher
-Uses previous key stream to form next keystream - 45What is CTR?- Counter Mode
- Uses increment counter which is fed into key stream
- Each block has different key stream - 46What are 4 3DES modes?- 3DES-EEE3
- 3DES-EDE3
- 3DES-EEE2
- 3DES-EDE2 - 47What is 3DES-EEE3?- Blocks are encrypted 3 times with a different key
- 48What is 3DES-EDE3?Block data is encrypted with the first key, decrypted with the second and encrypted with the third.
- 49What is 3DES-EEE2?Each block of data is encrypted with the first key, encrypted with the second key and encrypted again with the first key
- 50What is 3DES-EDE2?Each block of data is encrypted with the first key, decrypted with the second key and encrypted again with the first key
- 51What are some strengths of symmetric algorithms?- 1000 to 10000 times faster than asymmetric
- Hard to break
- Cheaper to implement - 52What are some weaknesses of symmetric algorithms?- Number of unique keys makes it harder to manage
- Secure key distribution is most important
- Security compromised if one party is - 53What are some strengths of asymmetric algorithms?- Key distribution is easier to manage
- Key management is easier due to everyone using same public key - 54What are some weaknesses of asymmetric algorithms?- More expensive to implement
- 1000 to 10000 times slower than symmetric algorithms - 55What is DRM?Digital Rights Management
- Controls use of digital content - 56What is GPG?GNU Privacy Guard
- Used to protect electronic comms
- Upgrade of PGP and uses AES - 57What is PGP?Pretty Good Privacy
- Uses RSA for encryption
- Web of trust for key management
- Share public keys with everyone. - 58What is SSL/TLS and what are two ways it can be implemented?Secure Sockets Layer
Transport Layer Security
- SSL Portal VPN
- SSL Tunnel VPN - 59What is an SSL Portal VPN?- Where a user can have a single SSL connection to multiple services on a web server.
- Once authenticated, user has access to other services - 60What is an SSL Tunnel VPN?Uses an SSL tunnel to access services on a server that is NOT a web server.
- 61Which SSL version must be used on client side authentication?SSL-2
- 62What S/MIME?Secure Multipurpose Internet Mail Extensions
- Allows email to include attachments
- S/MIME allows MIME to encrypt and digitally sign emails.
- Provides confidentiality, integrity, authentication and non-repudiation - 63What is diffusion?The process of changing the location of plain text within cipher text.
- 64How is diffusion carried out?Through transposition or permutation. This is the process of shuffling or reordering the plain text to hide original.
- 65What are some popular asymmetric algorithms?Diffie-Hellman, RSA, El Gamal, ECC, Knapsack and Zero Knowledge Proof
- 66What are some popular symmetric algorithms?DES, AES, IDEA, Skipjack, Blowfish, Twofish, RC4/RC5/RC6 and CAST
- 67What is key clustering?When different encryption keys are used to generate the same cipher text from the same plain text.
- 68What is cryptanalysis?The science of decrypting cipher-text without prior knowledge of the key or crypto system used.
- 69What is PFS and what is it used for?Perfect Forward Secrecy
Increases the security for a VPN because it ensures the same key will not be generated by forcing a new key exchange.
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- Descripción
- Select appropriate cryptographic concepts and techniques
- Creado por
- DJ Perrone
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