Cryptography

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Author:
WOBC1812
ID:
304855
Filename:
Cryptography
Updated:
2015-07-06 21:18:37
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Crypto
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Description:
Domain 1 - Cryptography
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  1. Cryptography provides 4 essential services:
    • Confidentiality
    • Integrity
    • Authentication
    • Non-repudiation
  2. A _____ is a type of encryption, which has been proven to be impossible to to crack if used correctly.
    One-time pad (OTP)
  3. What is a way to make a short cryptovariable longer so that it is more immune from attack. Give two examples.
    • Key Stretching
    • Salting a password: 
    • PBKDF2
    • Bcrypt()
  4. What are three types of substitution Ciphers?
    • Shift Cipher
    • Mono-alphabetic Cipher
    • Polyalphabetic Cipher
  5. What is Steganography and some usages?
    • Process of hiding or concealing one's message within something else
    • Least significant bits

    • Examples: 
    • Removing two color bits from a picture and replacing with message / virus
  6. What is cryptography?
    The study of encryption.
  7. _____ is converting information to a secret format / cipher text. _______ is conversion back to plain text.
    Encryption ; decryption
  8. _______ ______ uses _ separate networks working simultaneously to authenticate a user.
    Out-of-Band Authentication; 2
  9. ________ uses the same key to encrypt or decrypt.
    Symmetric Encryption
  10. Give some AKAs for Symmetric Encryption and give one advantage and disadvantage.
    • AKA: Single, same, secret and session key
    • Advantage: fastest form of encryption
    • Disadvantage: unique key to each party
  11. ______ solves key distribution problem. Has a public and private key pair.
    Asymmetric encryption
  12. Asymmetric encryption uses a ______ that is freely distributed to encrypt, and a _____ that is secret to decrypt.
    Public; Private
  13. List meaning of, block, key size and type for the following: 
    AES
    • Advanced Encryption Standard (based on Rijndael cipher)
    • Block: 128
    • Bits: 128, 192, 256
    • Type: Symmetrical
  14. List meaning of, block, key size and type for the following: Blowfish?
    • Block size: 64
    • Key size: 32 to 448
    • Type: Symmetrical
  15. List meaning of, block, key size and type for the following: CAST-128
    • Carlisle Adams/Stafford Tavares
    • Block: 64
    • Bit: 40-128
    • Type: Symmetrical
  16. List meaning of, block, key size and type for the following: DES
    • Data Encryption Standard
    • Block: 64 
    • Key: 56 bits
    • Type: Symmetrical
  17. List meaning of, block, key size and type for the following: IDEA
    • International Data Encryption Algorithm
    • Block: 64
    • Key: 128
    • Type: Symmetrical
  18. List meaning of, block, key size and type for the following: RC5
    • Rivest Cipher 5
    • Block: 32, 64, 128
    • Key: 0-2040
    • Type: Symmetrical
  19. List meaning of, block, key size and type for the following: RC6
    • Rivest Cipher 6
    • Block: 128
    • Key: 128, 192, or 256
    • Type: Symmetrical
  20. List meaning of, block, key size and type for the following: 3DES
    • Triple Data Encryption Standard
    • Block: 64
    • Key: 168
    • Type: Symmetrical
  21. List meaning of, block, key size and type for the following: Twofish
    • Twofish
    • Block: 128
    • Key: 168
    • Type: Symmetrical
  22. List meaning of, block, key size and type for the following: RC4
    • Rivest Cipher 4
    • Stream Cipher
    • variable key length: 0-2048
  23. List meaning of, block, key size and type for the following: SAFER
    • Secure and Fast Encryption Routine
    • Block: 128 Bit 
    • used for Bluetooth
  24. _______ encrypt one character of data at a time. The output is the same size as the input.
    Stream Cipher
  25. ______ covers encryption data in transit. Gives some examples.
    • Transport Encryption
    • Examples: VPN, SSL, TLS, HTTPS, SSH.
  26. ______ is the concept that a sender cannot deny sending a message and is provided by a hash.
    Non-repudiation
  27. _____ takes a variable sized input, runs it through an algorithm and creates a fixed output. Proves authentication.
    Hashing
  28. A ____ is when two inputs provide the same hash. What can prevent this?
    collision; Longer hashes are more collision resistant.
  29. In asymmetric encryption there are four keys, what are they?
    • Public Key of sender
    • Private key of the sender
    • Public key of the recipient
    • Private key of the recipient
  30. List meaning of, block, key size and type for the following: Diffie-Hellman
    • First asymmetric algorithm
    • provided for key exhange
    • based on difficulty of computing discrete logarithms
    • Variable key length
    • 512-bit to arbitrarily long
    • 1024-2048 considered secure
    • Same strength as 3072-bit RSA key
  31. Give brief synopsis of: El Gamal
    • Encryption, Digital Signatures, Key exhanges
    • Based on Diffie-Hellman
    • Slower than comparable algorithms.
  32. Give brief synopsis of: RSA
    • Rivest, Shamir, Adleman
    • Encryption, Digital Signatures, Key Exchange
    • De facto standard
    • Variable block and key length
    • 512-bit to arbitrarily long
    • 1024-2048 considered secure
    • Used in PGP

    Can be 100 times slower than conventional encryption software; 1000-10000 slower than hardware.
  33. Give brief synopsis of: ECC
    • Elliptic Curve Cryptography
    • Encryption, Digital Signatures, Key exchange
    • Requires less computing power
    • 160 bit ECC is equivalent to 1024bit RSA
    • Use on wireless and smart cards
  34. _____: The length of the key is equal to the length of the data. The key has variable offsets for each character; virtually unbreakable.
    One-Time Pad (OTP)
  35. ____ would be used to send an encrypted email.
    S/MIME
  36. PKI elements:
    • Certificate Authorities (CA)
    • Certificates
    • PKI
    • recovery agents
    • public key
  37. ____ issues keys and maintains the CRL
    Certificate Authorities
  38. The standard format for digital certificates is what?
    x.509
  39. What is included in a digital certificate?
    • Certificate verision
    • certificate holder's public key
    • serial number
    • Distinguished name
    • validity period
    • unique name of cert issuer
    • digital signature of issuer
    • signature algorithm identifier
  40. What is a CSR?
    Certificate Signing Request; it is a request from an applicant to a CA for a certificate.
  41. The ___ contains a list of certificates that are compromised and invalid. It is comprised of public keys
    CRL; Certificate Revocation List
  42. An alternate to the CRL is the ____; use it to check individual certificates.
    Online Certificate Status Protocol (OCSP)
  43. What are some types of trust models?
    • Single-Authority Trust (third-party trust)
    • Hierarchical trust
    • Bridge trust
    • WEB of trust

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