ECCouncil 212-81 Practice Test - Questions Answers, Page 20

Speed

Symmetric key systems are considerably faster than asymmetric key systems but have issues with proper key distribution, controlling keys as more users need to communicate, and cannot provide non-repudiation or authenticity.

TLS

https://en.wikipedia.org/wiki/Transport_Layer_Security#History_and_development

TLS 1.0 was first defined in RFC 2246 in January 1999 as an upgrade of SSL Version 3.0, and written by Christopher Allen and Tim Dierks of Consensus Development. As stated in the RFC, 'the differences between this protocol and SSL 3.0 are not dramatic, but they are significant enough to preclude interoperability between TLS 1.0 and SSL 3.0'. Tim Dierks later wrote that these changes, and the renaming from 'SSL' to 'TLS', were a face-saving gesture to Microsoft, 'so it wouldn't look [like] the IETF was just rubberstamping Netscape's protocol'.

Registration authority

https://en.wikipedia.org/wiki/Registration_authority

Registration authorities exist for many standards organizations, such as ANNA (Association of National Numbering Agencies for ISIN), the Object Management Group, W3C, IEEE and others. In general, registration authorities all perform a similar function, in promoting the use of a particular standard through facilitating its use. This may be by applying the standard, where appropriate, or by verifying that a particular application satisfies the standard's tenants. Maintenance agencies, in contrast, may change an element in a standard based on set rules -- such as the creation or change of a currency code when a currency is created or revalued (i.e. TRL to TRY for Turkish lira). The Object Management Group has an additional concept of certified provider, which is deemed an entity permitted to perform some functions on behalf of the registration authority, under specific processes and procedures documented within the standard for such a role.

Output feedback (OFB)

https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Output_feedback_(OFB)

The output feedback (OFB) mode makes a block cipher into a synchronous stream cipher. It generates keystream blocks, which are then XORed with the plaintext blocks to get the ciphertext. Just as with other stream ciphers, flipping a bit in the ciphertext produces a flipped bit in the plaintext at the same location. This property allows many error-correcting codes to function normally even when applied before encryption.

Incorrect answers:

Cipher feedback (CFB)- mode, a close relative of CBC, makes a block cipher into a self-synchronizing stream cipher.

Electronic codebook (ECB)- the simplest of the encryption modes (named after conventional physical codebooks). The message is divided into blocks, and each block is encrypted separately.

Cipher-block chaining (CBC)- Ehrsam, Meyer, Smith and Tuchman invented the cipher block chaining (CBC) mode of operation in 1976. In CBC mode, each block of plaintext is XORed with the previous ciphertext block before being encrypted. This way, each ciphertext block depends on all plaintext blocks processed up to that point. To make each message unique, an initialization vector must be used in the first block.

GOST

https://en.wikipedia.org/wiki/GOST_(hash_function)

The GOST hash function, defined in the standards GOST R 34.11-94 and GOST 34.311-95 is a 256-bit cryptographic hash function. It was initially defined in the Russian national standard GOST R 34.11-94 Information Technology -- Cryptographic Information Security -- Hash Function. The equivalent standard used by other member-states of the CIS is GOST 34.311-95.

Incorrect answers:

BEAR - BEAR block cipher was invented by Ross Anderson and Eli Biham by combining a stream cipher and a cryptographic hash function.

TIGER - is a cryptographic hash function designed by Ross Anderson and Eli Biham in 1995 for efficiency on 64-bit platforms. The size of a Tiger hash value is 192 bits. Truncated versions (known as Tiger/128 and Tiger/160) can be used for compatibility with protocols assuming a particular hash size. Unlike the SHA-2 family, no distinguishing initialization values are defined; they are simply prefixes of the full Tiger/192 hash value.

FORK-256 - is a hash algorithm designed in response to security issues discovered in the earlier SHA-1 and MD5 algorithms. After substantial cryptanalysis, the algorithm is considered broken.

Key escrow

https://en.wikipedia.org/wiki/Key_escrow

Key escrow (also known as a ''fair'' cryptosystem) is an arrangement in which the keys needed to decrypt encrypted data are held in escrow so that, under certain circumstances, an authorized third party may gain access to those keys. These third parties may include businesses, who may want access to employees' secure business-related communications, or governments, who may wish to be able to view the contents of encrypted communications (also known as exceptional access).

Homophonic Substitution

https://en.wikipedia.org/wiki/Substitution_cipher#Homophonic_substitution

An early attempt to increase the difficulty of frequency analysis attacks on substitution ciphers was to disguise plaintext letter frequencies by homophony. In these ciphers, plaintext letters map to more than one ciphertext symbol. Usually, the highest-frequency plaintext symbols are given more equivalents than lower frequency letters. In this way, the frequency distribution is flattened, making analysis more difficult.

Incorrect answers:

Playfair Cipher - (Playfair square or Wheatstone-Playfair cipher) is a manual symmetric encryption technique and was the first literal digram substitution cipher. The scheme was invented in 1854 by Charles Wheatstone, but bears the name of Lord Playfair for promoting its use.

Scytale Cipher - is a tool used to perform a transposition cipher, consisting of a cylinder with a strip of parchment wound around it on which is written a message. The ancient Greeks, and the Spartans in particular, are said to have used this cipher to communicate during military campaigns.

ADFVGX Cipher - cipher was a field cipher used by the German Army on the Western Front during World War I. ADFGVX was in fact an extension of an earlier cipher called ADFGX. Invented by Lieutenant Fritz Nebel (1891--1977) and introduced in March 1918, the cipher was a fractionating transposition cipher which combined a modified Polybius square with a single columnar transposition.

RSA

https://en.wikipedia.org/wiki/RSA_(cryptosystem)

RSA (Rivest--Shamir--Adleman) is a public-key cryptosystem that is widely used for secure data transmission. It is also one of the oldest. The acronym RSA comes from the surnames of Ron Rivest, Adi Shamir, and Leonard Adleman, who publicly described the algorithm in 1977.

Kerberos

https://en.wikipedia.org/wiki/Kerberos_(protocol)

Kerberos is a computer-network authentication protocol that works on the basis of tickets to allow nodes communicating over a non-secure network to prove their identity to one another in a secure manner. The protocol was named after the character Kerberos (or Cerberus) from Greek mythology, the ferocious three-headed guard dog of Hades. Its designers aimed it primarily at a client--server model and it provides mutual authentication---both the user and the server verify each other's identity. Kerberos protocol messages are protected against eavesdropping and replay attacks.

Kerberos builds on symmetric key cryptography and requires a trusted third party, and optionally may use public-key cryptography during certain phases of authentication. Kerberos uses UDP port 88 by default.

Incorrect answers:

ElGamal - ElGamal encryption system is an asymmetric key encryption algorithm for public-key cryptography which is based on the Diffie--Hellman key exchange. It was described by Taher Elgamal in 1985. ElGamal encryption is used in the free GNU Privacy Guard software, recent versions of PGP, and other cryptosystems. The Digital Signature Algorithm (DSA) is a variant of the ElGamal signature scheme, which should not be confused with ElGamal encryption.

Diffie-Hellman - Diffie--Hellman key exchange is a method of securely exchanging cryptographic keys over a public channel and was one of the first public-key protocols as conceived by Ralph Merkle and named after Whitfield Diffie and Martin Hellman.[1][2] DH is one of the earliest practical examples of public key exchange implemented within the field of cryptography. Published in 1976 by Diffie and Hellman, this is the earliest publicly known work that proposed the idea of a private key and a corresponding public key.

Yarrow - algorithm is a family of cryptographic pseudorandom number generators (CPRNG) devised by John Kelsey, Bruce Schneier, and Niels Ferguson and published in 1999. The Yarrow algorithm is explicitly unpatented, royalty-free, and open source; no license is required to use it. Yarrow is incorporated in iOS and macOS for their /dev/random devices, and was in FreeBSD (where it is superseded by Fortuna).