Description : The responsibility of a certification authority for digital signature is to authenticate the a. hash function used b. private keys of subscribers c. public keys of subscribers d. key used in DES
Last Answer : c. public keys of subscribers
Description : Encryption of data is important to ensure its privacy. It is most commonly achieved by using a ____. A. public-key encryption B. private-key encryption C. password-key encryption D. character set encryption
Last Answer : A. public-key encryption
Description : DES works by using a. permutation and substitution on 64 bit blocks of plain text b. only permutations on blocks of 128 bits c. exclusive ORing key bits with 64 bit blocks d. 4 rounds of substitution on 64 bit blocks with 56 bit keys
Last Answer : a. permutation and substitution on 64 bit blocks of plain text
Description : A seven-bit character can represent one of _________ possibilities. A. 14 B. 64 C. 128 D. 7
Last Answer : C. 128
Description : Suppose a digitized voice channel is made by digitizing 8 kHz bandwidth analog voice signal. It is required to sample the signal at twice the highest frequency (two samples per hertz). What is the bit rate required, if it ... sample requires 8 bits? (A) 32 kbps (B) 64 kbps (C) 128 kbps (D) 256 kbps
Last Answer : (C) 128 kbps
Description : All bits in character are sent and received ______ in serial port. A. In groups of 3 bits B. One at a time C. In groups of 2 bits D. Simultaneously
Last Answer : B. One at a time
Description : One of the problems with using SET protocol is a. the merchant's risk is high as he accepts encrypted credit card b. the credit card company should check digital signature c. the bank has to ... of all customers d. the bank has to keep a database of digital signatures of all customers
Last Answer : c. the bank has to keep a database of the public keys of all customers
Description : In public key encryption system if A encrypts a message using his private key and sends it to B a. if B knows it is from A he can decrypt it using A's public key b. Even if B knows who sent the ... be decrypted at all as no one knows A's private key d. A should send his public key with the message
Last Answer : a. if B knows it is from A he can decrypt it using A’s public key
Description : Codes must be A. agreed upon in advance between sender and receiver B. eight bit per character C. the same in all modern computer D. either seven or eighth bits per character
Last Answer : A. agreed upon in advance between sender and receiver
Description : A statement (Sk-82) showing particulars of the articles of stock supplied during each month to offices by local purchase, or by transfer either from other offices or from the reserve stock kept ... , Head office , Divisional head c) Superintendent, Circle office , Divisional head d) None of these
Last Answer : a) Superintendent, stock depot , Divisional head
Description : A 8-Mbps tokenring has atoken holding timer value of 10 msec. What is the longest frame (assumeheader bits are negligible) that canbe sent on this ring? A. 8000 B frame B. 80,000 B frame C. 8 x 105 bit frame D. 10,000 B frame
Last Answer : 10,000 B frame
Description : An analog signal carries 4 bits in each signal unit. If 1000 signal units are sent per second, then baud rate and bit rate of the signal are ............... and .............. (A) 4000 bauds \ sec & ... (B) 2000 bauds \ sec & 1000 bps (C) 1000 bauds \ sec & 500 bps (D) 1000 bauds \ sec & 4000 bps
Last Answer : (D) 1000 bauds \ sec & 4000 bps Explanation: Bit rate is the number of bits per second. Baud rate is the number of signal units per second. Baud rate is less than or equal to the bit rate. Baud rate = 1000 bauds per second (baud/s) Bit rate = 1000 x 4 = 4000 bps
Description : What term is used to describe a spread spectrum communications system in which a very fast binary bit stream is used to shift the phase of an RF carrier? A. Frequency hopping B. Direct sequence C. Binary phase-shift keying D. Phase compandored spread spectrum
Last Answer : B. Direct sequence
Description : Certification of Digital signature by an independent authority is needed because a. it is safe b. it gives confidence to a business c. the authority checks and assures customers that the public ... business which claims its ownership d. private key claimed by a sender may not be actually his
Last Answer : c. the authority checks and assures customers that the public key indeed belongs to the business which claims its ownership
Description : Bits can be sent over guided and unguided media as analog signal by ___________ a. digital modulation b. amplitude modulation c. frequency modulation d. phase modulation
Last Answer : a. digital modulation
Description : Which is/are the main provisions of Information Technology (IT) Act, 2000? 1) Finalisation of contracts through electronic media. 2) Legal recognition to digital signatures and documents. 3) Making hacking with computer system an office. 4) All of the above
Last Answer : 4) All of the above
Description : Sources of impulse noise induced in communication channels. A. Erroneous digital coding bit caused by an error on a transmission facility B. Transients due to relay operation C. Crosstalk from dc signaling systems D. All of these
Last Answer : D. All of these
Description : What is the propagation delay when a signal is transmitter by an earth station to a geosynchronous satellite about 38,500 km above earth’s equator and then received by the same earth station? A. 256 msec B. 128 msec C. 300 msec D. 400 msec
Last Answer : A. 256 msec
Description : What bandwidth is needed to support a capacity of 128 kbps when the signal power to noise power ratio in decibels is 100? A. 19224 Hz B. 3853 Hz C. 19244 Hz D. 3583 Hz
Last Answer : B. 3853 Hz
Description : What is the number of levels required in a PCM system with S/N ratio of 40 dB? A. 64 B. 128 C. 256 D. 512
Last Answer : B. 128
Description : What is the transmission rate of a GSM cellular system? A. 64 kbps B. 240 kbps C. 128 kbps D. 270 kbps
Last Answer : D. 270 kbps
Description : In the question a part of the sentence is given in BOLD. Alternatives to the BOLD part are given which may improve the construction of the sentence. Select the correct alternative. There are not many men who ... to by their short names only (a) initials (b) signatures (c) pictures (d) middle names
Last Answer : (a) initials
Description : If h is chosen from a universal collection of hash functions and is used to hash n keys into a table of size m, where n ≤ m, the expected number of collisions involving a particular key K is (A) less than 1 (B) less than lg n (C) greater than 1 (D) greater than lg n
Last Answer : (A) less than 1
Description : Consider a hash table of size m=100 and the hash function h(k) = floor(m(kA mod 1)) for A = (√5 − 1)/2 = 0.618033. Compute the location to which the key k = 123456 is placed in hash table. (A) 77 (B) 82 (C) 88 (D) 89
Last Answer : (C) 88
Description : If h is chosen from a universal collection of hash functions and is used to hash n keys into a table of size m, where n≤m, the expected number of collisions involving a particular key x is less than ................... (1) 1 (2) 1/n (3) 1/m (4) n/m
Last Answer : Answer: 1
Description : Adding bits to synchronize one digital signal to another is called: a. bit stuffing b. bit-synch c. SDH d. WDM
Last Answer : a. bit stuffing
Description : An IPv6address is _________ bits long. A) 32 B) 64 C) 128 D) none of the above
Last Answer : 128
Description : Which of the following statement is true? I. An address with all bits 1 is interpreted as all networks or all hosts. II. The class A network 128.0.0.0 is defined as the loopback network. a. i only b. ii only c. Both A and B d. None of the above
Last Answer : a. i only
Description : An IPv6 address is _________ bits long A. 32 B. 64 C. 128 D. none of the above
Description : Due to the growth of the internet and the predicted depletion of available addresses, a new version of IP version 6 using _____for the address was developed in 1995: a) 128 Bits b) 129 Bits c) 130 Bits d) None of These
Last Answer : a) 128 Bits
Description : Which of the following statement is true? i) An address with all bits 1 is interpreted as all networks or all hosts. ii) The class A network 128.0.0.0 is defined as the loopback network. A) i only B) ii only C) Both A and B D) None of the above
Last Answer : A) i only
Description : Which of the following statement is true? i) An address with all bits 1 is interpreted as all networks or allhosts. ii) The class A network 128.0.0.0 is defined as the loopbacknetwork. A) i only B) ii only C) Both A and B D) None of the above
Description : What is size of the IPv6 Address? A. 32 bits B. 64 bits C. 128 bits D. 256 bits
Last Answer : C. 128 bits
Description : Type of emission produced by one of the early radio transmitter in trains of damped RF ac waves where its oscillator is coupled to a long wire antenna, normally used in radio telegraph and having sidebands on its carrier. A. Digital emission B. Key emission C. Cycle emission D. Spark emission
Last Answer : D. Spark emission
Description : Court will take judicial notice of the following - a) All laws in force in territory of India b) The accession to office names, titles, functions and signatures of the persons filling for the ... of hostilities between the Government of India and any other state or body d) All the above
Last Answer : d) All the above
Description : ECE Board Exam March 1996 One character or a sequence of characters forming a part, or the whole of a message with a specific meaning A. Signs B. Call sign C. Code D. Identifier
Last Answer : C. Code
Description : Following statements are talking about . 1. It's more complex than a hybrid cloud, which is typically a paired private and public cloud. 2. This cloud add more clouds to the mix, perhaps two ... , private use-based accounting A. Multi-Cloud B. Private Cloud C. Business Cloud D. Storage Cloud
Last Answer : Multi-Cloud
Description : Find the false statement: (A) In Modern Cryptography, symmetric key algorithms use same key both for Encryption and Decryption. (B) The Symmetric cipher DES (Data Encryption Standard) was widely used ... and 124 bits. (D) Public key algorithms use two different keys for Encryption and Decryption.
Last Answer : (C) The AES (Advanced Encryption Standard) cryptosystem allows variable key lengths of size 56 bits and 124 bits.
Description : What do you call the phenomenon in digital circuits that describe the duration of time a digital signal passes a circuit? A. Transmission time B. Elapsed time C. Propagation delay D. Travel delay
Last Answer : C. Propagation delay
Description : In hexadecimal colon notation, a 128-bit address isdivided into _______ sections, each _____hexadecimal digits in length. A) 8: 2 B) 8: 3 C) 8: 4 D) none of the above
Last Answer : 8: 4
Description : IPv6 has _______ -bit addresses. A. 32 B. 64 C. 128 D. Variable
Description : What is the size of an IP address? A. 64 bit B. 128 bit C. 16 bit D. 32 bit
Last Answer : D. 32 bit
Description : The SP is of ___ wide register. And this may be defined anywhere in the ______. a) 8 byte, on-chip 128 byte RAM. b) 8 bit, on chip 256 byte RAM. c) 16 bit,
Last Answer : a) 8 byte, on-chip 128 byte RAM.
Description : ROM d) 8 bit, on chip 128 byte RAM. 3. After reset, SP register is initialized to address________. a) 8H b) 9H c) 7H d) 6H
Last Answer : c) 7H
Description : Triple DES uses a. 168 bit keys on 64-bit blocks of plain text b. Working on 64-bit blocks of plain text and 56 bit keys by applying DES algorithm for three rounds. c. Works with 144 bit ... algorithm once. d. Uses 128 bit blocks of plain text and 112 bit keys and apply DES algorithm thrice.
Last Answer : b. Working on 64-bit blocks of plain text and 56 bit keys by applying DES algorithm for three rounds.
Description : What do the following numbers have in sequence - 512-256-128-64?
Last Answer : It is a geometric progression with common ratio 0.5
Description : Message can be sent more securely using DES by a. encrypting plain text by a different randomly selected key for each transmission b. encrypting plain text by a different random key for each ... instead of using hardware d. designing DES with high security and not publicizing algorithm used by it
Last Answer : b. encrypting plain text by a different random key for each message transmission and sending the key to the receiver using a public key system
Description : A digital signature is a. a bit string giving identity of a correspondent b. a unique identification of a sender c. an authentication of an electronic record by tying it uniquely to a key only a sender knows d. an encrypted signature of a sender
Last Answer : c. an authentication of an electronic record by tying it uniquely to a key only a sender knows
Description : What is the minimum number of bits required in a PCM code for a range of 10,000? A. 12 B. 9 C. 14 D. 10
Last Answer : C. 14