_____ uses at least two different shifts, changing the shift with different letters in the plain text.
Answer(s): B
multi-alphabet encryption https://en.wikipedia.org/wiki/Polyalphabetic_cipherTwo different shifts create two different alphabets.For +1 and +2Plaintext alphabetA B C D E F G H I J K L M N O P Q R S T U V W X Y Z2 ciphertext alphabetsB C D E F G H I J K L M N O P Q R S T U V W X Y Z AC D E F G H I J K L M N O P Q R S T U V W X Y Z A BIncorrect answers:Scytale - transposition cipherCaesar cipher - monoalphabetic cipherAtbash - monoalphabetic cipher
Jane is looking for an algorithm to ensure message integrity. Which of following would be an acceptable choice?
Answer(s): D
Integrity. In information security, data integrity means maintaining and assuring the accuracy and completeness of data over its entire lifecycle. This means that data cannot be modified in an unauthorized or undetected manner.An important application of hashes is verification of message integrity. Comparing message digests (hash digests over the message) calculated before, and after, transmission can determine whether any changes have been made to the message or file.SHA-1https://en.wikipedia.org/wiki/SHA-1SHA-1 (Secure Hash Algorithm 1) is a cryptographic hash function which takes an input and produces a 160-bit (20-byte) hash value known as a message digest typically rendered as a hexadecimal number, 40 digits long. It was designed by the United States National Security Agency, and is a U.S.Federal Information Processing Standard.Incorrect answers:RSA (RivestShamirAdleman) is one of the first public-key cryptosystems and is widely used for secure data transmission.RC4 (Rivest Cipher 4 also known as ARC4 or ARCFOUR meaning Alleged RC4, see below) is a stream cipher.AES (Advanced Encryption Standard) is a subset of the Rijndael block cipher
If you wished to see a list of revoked certificates from a CA, where would you look?
Answer(s): C
CRLhttps://ru.wikipedia.org/wiki/Certificate_Revocation_List Certificate Revocation List (or CRL) is "a list of digital certificates that have been revoked by the issuing certificate authority (CA) before their scheduled expiration date and should no longer be trusted".Incorrect answers:RA - Used to proxy the certificate requests on behalf of the user and validate whether or not they are legitimate instead of having the user go directly to the CA. The RA talks to the subordinate CA on behalf of the user, which makes it harder for the actor to get directly to the certificate authority and do harm.RFC Request for Comments (RFC) is a publication from the Internet Society (ISOC) and its associated bodies, most prominently the Internet Engineering Task Force (IETF), the principal technical development and standards-setting bodies for the Internet. CA - certificate authority or certification authority is an entity that issues digital certificates
Which of the following are valid key sizes for AES (choose three)?
Answer(s): A,C,D
Correct answers: 128, 192, 256https://en.wikipedia.org/wiki/Advanced_Encryption_Standard The Advanced Encryption Standard (AES), also known by its original name Rijndael, is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001.AES is a subset of the Rijndael block cipher developed by two Belgian cryptographers, Vincent Rijmen and Joan Daemen, who submitted a proposal to NIST during the AES selection process. Rijndael is a family of ciphers with different key and block sizes. For AES, NIST selected three members of the Rijndael family, each with a block size of 128 bits, but three different key lengths: 128, 192 and 256 bits.
A cipher is defined as what
Answer(s): A
The algorithm(s) needed to encrypt and decrypt a message https://en.wikipedia.org/wiki/CipherIn cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption--a series of well-defined steps that can be followed as a procedure. An alternative, less common term is encipherment. To encipher or encode is to convert information into cipher or code. In common parlance, "cipher" is synonymous with "code", as they are both a set of steps that encrypt a message; however, the concepts are distinct in cryptography, especially classical cryptography.
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