Sis Prvi Kolokvijum Teorija
Anihanibani RT24-14
- 1.
Vrhovni CA je potpisan od strane
- A.
Samog sebe
- B.
Njemu ravnopravnog CA
- C.
Države
- D.
Ničeg od navedenog
Correct Answer
A. Samog sebeExplanation
The correct answer is "Samog sebe". This means that the Supreme CA (Certification Authority) signs itself, indicating that it is its own authority and does not require validation or authorization from any other entity. This suggests that the Supreme CA has the highest level of trust and autonomy in issuing and managing digital certificates.Rate this question:
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- 2.
Tehnikom image downgrading-a
- A.
Moguce je BMP sakriti u BMP
- B.
Moguce je JPEG sakriti u JPEG
- C.
Moguce je JPEG sakriti u BMP
- D.
Moguce je BMP sakriti u JPEG
Correct Answer
A. Moguce je BMP sakriti u BMPExplanation
The given answer states that it is possible to hide a BMP image within another BMP image. This means that one BMP image can be embedded or concealed within another BMP image without altering the file format. This technique is known as image downgrading, where one image is hidden within another to hide information or to achieve a certain effect.Rate this question:
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- 3.
OTP je bezuslovno sigurna šifra
- A.
Uz određene uslove
- B.
Dokazano
- C.
Bezuslovno sigurne šifre nema
- D.
Pretpostavljano
Correct Answer
B. DokazanoExplanation
The given correct answer is "Dokazano". This suggests that it has been proven or demonstrated that OTP (One-Time Password) is unconditionally secure. OTP is a type of password that is valid for only one login session or transaction, on a computer system or other digital device. It is considered highly secure because it is generated for each use and cannot be reused or intercepted by attackers. The use of OTP eliminates the risk of password theft or unauthorized access, making it a reliable and secure method of authentication.Rate this question:
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- 4.
Bezuslovno sigurna sifra
- A.
је OTP шифра
- B.
не постоји
- C.
је ECB
- D.
је кодна књига
Correct Answer
A. је OTP шифраExplanation
The correct answer is "је OTP шифра". This is because OTP (One-Time Password) is a type of encryption where a unique password is generated for each authentication attempt. It provides a high level of security as the password is only valid for a single use or a short period of time. Therefore, OTP encryption is unconditionally secure and considered one of the most secure methods of encryption available.Rate this question:
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- 5.
OTP šifra može da se koristi
- A.
Samo jednom
- B.
Samo dva puta
- C.
Najvise 5 puta
- D.
Nema pravila vezanog za koriscenje
Correct Answer
A. Samo jednomExplanation
The correct answer is "samo jednom" which means "only once" in English. This suggests that the OTP (One-Time Password) code can be used for a single time only and cannot be reused or used multiple times. This is a common security measure to ensure that the password remains unique and cannot be compromised or intercepted by unauthorized individuals.Rate this question:
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- 6.
Koje operacije se koriste kod OTP sifre
- A.
Samo supstitucije
- B.
Samo trenaspozicije
- C.
Samo XOR
- D.
XOR i supstitucije
Correct Answer
C. Samo XORExplanation
The correct answer is "samo XOR" because OTP (One-Time Pad) encryption method uses only the XOR (exclusive OR) operation. In OTP, each character of the plaintext is combined with a character from a random key using XOR, resulting in the ciphertext. XOR is a bitwise operation that produces a 1 if the corresponding bits of the operands are different, and 0 if they are the same. This operation ensures that the encryption is secure, as long as the key is truly random and used only once.Rate this question:
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- 7.
Pseudo slučajan niz brojeva se koristi
- A.
Kao ključ za sekvencijalne šifarske sisteme
- B.
Za generisanje potpuno slučajnog ključa za OTP šifru
- C.
Kao podključ za blokovske šifarske sisteme
- D.
Za sve navedeno
Correct Answer
A. Kao ključ za sekvencijalne šifarske sistemeExplanation
A pseudo-random number sequence is used as a key for sequential cipher systems.Rate this question:
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- 8.
Sekvencijalni algoritmi se koriste
- A.
Tamo gde je bitna brzina i rad u realnom vremenu
- B.
Kao deo vecih sifrarskih sistema
- C.
Ne koriste se vise
- D.
Tamo gde je bitno da sifrat bude prenet bez greske
Correct Answer
A. Tamo gde je bitna brzina i rad u realnom vremenuExplanation
Sequential algorithms are used in situations where speed and real-time processing are important, such as in larger cryptographic systems. They are not used in situations where it is important for the cipher to be transmitted without errors.Rate this question:
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- 9.
Kod OTP sifre, duzina kljuca:
- A.
Je iste duzine kao otvoreni tekst
- B.
Zavisi od algoritma koji se koristi za generisanje kljuca
- C.
Je iste ili vece duzine ali se odredjenim algoritmom skracuje na potrebnu duzinu.
- D.
је фиксне дужине за дати алгоритам, па се из њега генерише кључ потребне величине
Correct Answer
A. Je iste duzine kao otvoreni tekstExplanation
The correct answer states that the length of the OTP (One-Time Password) key is the same as the length of the plaintext. This means that for every character in the plaintext, there is a corresponding character in the OTP key, making them equal in length. This is important because it ensures that the OTP key is long enough to provide sufficient security and randomness for encryption purposes.Rate this question:
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- 10.
Nedostatak OTP sifre je to
- A.
Sto je tehnologija prenosa niza bitova velike duzine podlozna greskama prilikom prenosa
- B.
Kljuc mora biti slucajan niz bitova i ne sme da se prenosi nesigurnim kanalom sto znaci da druga strana za desifrovanje mora da generise isti takav slucajan niz bitova sto je nemoguce
- C.
Sto je proces generisanja velike kolicine binarnih nizova koji imaju osobine slucajnosti po pravilu spor a upotrebljava se samo jednom
- D.
Osnovni zahtev da kluc bude potpuno slucajan niz bitova sto je tehnicki neizvodljivo
Correct Answer
B. Kljuc mora biti slucajan niz bitova i ne sme da se prenosi nesigurnim kanalom sto znaci da druga strana za desifrovanje mora da generise isti takav slucajan niz bitova sto je nemoguceExplanation
The answer states that the key must be a random bit sequence and should not be transmitted through an insecure channel, which means that the other party needs to generate the same random bit sequence for decryption, which is impossible. Additionally, the process of generating a large amount of random binary sequences that have the properties of randomness is slow and can only be used once. The basic requirement for the key to be a completely random bit sequence is technically infeasible.Rate this question:
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- 11.
Kod OTP šifre
- A.
Dužina ključa mora biti jednaka dužini poruke i upotrebljava se samo jednom
- B.
Dužina ključa je nebitna jer se skraćuje/produžava na potrebnu dužinu i upotrebljava se samo jednom
- C.
Dužina ključa je nebitna jer se skraćuje/produžava na potrebnu dužinu i upotrebljava se samo dva puta
- D.
Dužina ključa je jednaka dužini poruke i može da se upotrebljava nekoliko puta
Correct Answer
A. Dužina ključa mora biti jednaka dužini poruke i upotrebljava se samo jednomExplanation
The correct answer is "Dužina ključa mora biti jednaka dužini poruke i upotrebljava se samo jednom." This means that the length of the key must be equal to the length of the message and it can only be used once. This ensures the security and confidentiality of the message by using a key that is unique to that specific message and cannot be reused.Rate this question:
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- 12.
Frekvencijska analiza nema efekta na
- A.
OTP
- B.
Vizenerovu
- C.
Hilovu
- D.
Plejferovu
Correct Answer
A. OTPExplanation
OTP stands for One-Time Pad, which is a cryptographic technique that uses a random key that is as long as the message being encrypted. This key is used only once and then discarded, making it impossible for anyone to decrypt the message without the key. Frequency analysis is a method used to break encryption by analyzing the frequency of letters or patterns in the encrypted message. However, since OTP uses a random key and each key is used only once, frequency analysis is ineffective against OTP encryption.Rate this question:
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- 13.
Simetrični algoritmi:
- A.
Imaju problem razmene ključeva
- B.
Koriste kraći ključ od asimetričnih algoritama
- C.
Sporiji su od asimetričnih
- D.
Koriste se isključivo za digitalno potpisivanje
Correct Answer
A. Imaju problem razmene ključevaExplanation
Symmetric algorithms have a problem with key exchange. This means that both parties involved in the communication need to have the same key in order to encrypt and decrypt the data. The challenge lies in securely exchanging this key between the parties without it being intercepted by unauthorized entities. Asymmetric algorithms, on the other hand, do not have this problem as they use different keys for encryption and decryption.Rate this question:
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- 14.
Trostruki DES :
- A.
Prvo šifruje sa prvim ključem, pa dešifruje sa drugim, pa šifruje sa prvim
- B.
Prvo šifruje sa prvim ključem, pa šifruje sa drugim, pa šifruje sa trećim
- C.
Prvo šifruje sa prvim ključem, pa šifruje sa drugim, pa dešifruje sa trećim
- D.
Prvo dešifruje sa prvim ključem, pa šifruje sa drugim, pa dešifruje sa trećim
Correct Answer
A. Prvo šifruje sa prvim ključem, pa dešifruje sa drugim, pa šifruje sa prvimExplanation
The correct answer is the option that states "Prvo šifruje sa prvim ključem, pa dešifruje sa drugim, pa šifruje sa prvim." This means that the encryption process starts by encrypting with the first key, then decrypting with the second key, and finally encrypting again with the first key. This sequence of encryption and decryption steps is known as triple DES (Data Encryption Standard) and provides enhanced security by applying multiple layers of encryption.Rate this question:
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- 15.
Da bi se smanjila dužina digitalnog potpisa poruke, računa se
- A.
Heš poruke koji se digitalno potpisuje
- B.
Ni jedno od navedenih
- C.
Heš šifrata koji se zatim digitalno potpisuje
- D.
Digitalni potpis, a zatim njegov heš
Correct Answer
A. Heš poruke koji se digitalno potpisujeExplanation
To reduce the length of a digital signature, the hash of the message is calculated and then digitally signed. This is because hashing algorithms can convert a message of any length into a fixed-length string of characters, which makes it more efficient to sign and verify the integrity of the message. By signing the hash of the message instead of the entire message, the digital signature becomes shorter and easier to handle.Rate this question:
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- 16.
ECB (Electronic Codebook Mode)
- A.
за шифровање текућег блока користи кључ К и шифрат претходног блока
- B.
шифрује блок отвореног текста тако што обави операцију XOR тог блока и шифрата претходног блока
- C.
шифрује блок по блок са истим кључем К
- D.
за шифровање блока отвореног текста користи подкључ генерисан из подкључа претходног блока и претходни блок отвореног текста
Correct Answer
C. шифрује блок по блок са истим кључем КExplanation
ECB (Electronic Codebook Mode) encrypts each block of plaintext separately using the same key K. It does not depend on the previous blocks or their ciphertexts for encryption. Each block of plaintext is encrypted by performing an XOR operation between that block and the ciphertext of the previous block. To encrypt a block of plaintext, a subkey is generated from the previous block's subkey and the previous block of plaintext.Rate this question:
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- 17.
Za hes funckije je vazno
- A.
Da budu efikasne
- B.
Da imaju sto siru primenu
- C.
Da budu invetibilne
- D.
Da im otisak - duzina bude sto duzi
Correct Answer
A. Da budu efikasneExplanation
The correct answer is "da budu efikasne" (to be efficient). This is because efficiency is important for the function to perform well and achieve its intended purpose. Efficiency ensures that the function uses minimal resources, time, and effort to produce the desired outcome. It allows for optimal utilization of resources and maximizes productivity. Therefore, it is crucial for functions to be efficient in order to be effective and successful.Rate this question:
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- 18.
Algoritam koji prilikom sifrovanja obradjuje blokove otvorenog teksta naziva se
Correct Answer
blokovski algoritamExplanation
The correct answer is "blokovski algoritam." This is because the question asks for the name of the algorithm that processes blocks of plaintext during encryption. "Blokovski algoritam" translates to "block algorithm" in English, which accurately describes the process of encrypting data in blocks rather than as a whole.Rate this question:
- 19.
AES moze da ima
- A.
10, 12 ili 14 rundi
- B.
14, 16 ili 18 rundi
- C.
8, 10 ili 12 rundi
- D.
12, 14 ili 16 rundi
Correct Answer
A. 10, 12 ili 14 rundiExplanation
The AES (Advanced Encryption Standard) can have 10, 12, or 14 rounds. The number of rounds in AES determines the level of security and encryption strength. The more rounds, the more secure the encryption, but also the slower the encryption process. The choice of the number of rounds depends on the specific security requirements and performance considerations of the application using AES.Rate this question:
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- 20.
U Difi Helmanovom broj p koji se koristi za stepenovanje po modlu p tokom izracunavanja
- A.
Moze da bude bilo koji prost broj
- B.
Moze da bude bilo koji veliki broj
- C.
Treba da bude proizvod dva velika prosta broja
- D.
Treba da bude veliki prost broj
Correct Answer
D. Treba da bude veliki prost brojExplanation
In the context of Diffie-Hellman key exchange, the prime number p used for modular exponentiation should be a large prime number. This is because using a large prime number enhances the security of the key exchange algorithm and makes it more difficult for attackers to calculate the shared secret key. The other options mentioned, such as any prime number, any large number, or the product of two large prime numbers, do not necessarily provide the same level of security as a large prime number.Rate this question:
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- 21.
Svojstvo sifrarskih algoritama tako da su kod napada potpunom pretragom kljuceva svi kljucevi podjednako verovatni naziva se
Correct Answer
svojstvo konfuzijeExplanation
The given correct answer states that the property of cryptographic algorithms where all keys are equally probable during a brute force attack is called the property of confusion. This means that the algorithm should provide a level of complexity and randomness in the relationship between the key and the cipher text, making it difficult for an attacker to determine the key through exhaustive search. The confusion property adds an additional layer of security by making it harder for an attacker to derive meaningful information from the cipher text without knowing the correct key.Rate this question:
- 22.
Sigurnost kriptosistema počiva na
- A.
Tajnosti ključa za šifrovanje
- B.
Bezbednosti kanala za komunikaciju
- C.
Tajnosti algoritam za sifrovanje
- D.
Tajnosti ključa za dešifrovanje
Correct Answer
D. Tajnosti ključa za dešifrovanjeExplanation
The security of a cryptosystem relies on the secrecy of the decryption key. The encryption key is used to encrypt the message, but it is the decryption key that is needed to decrypt the message and retrieve the original information. If the decryption key is not kept secret, an attacker could potentially obtain it and easily decrypt the encrypted messages, compromising the security of the system. Therefore, the secrecy of the decryption key is crucial for the security of the cryptosystem.Rate this question:
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- 23.
Difi Helmanov algoritam se koristi za
- A.
Razmenu simetričnih ključeva
- B.
Generisanje tajnog ključa na osnovu odabranog javnog
- C.
šifrovanje simetričnog ključa
- D.
Generisanje para ključeva (tajni-javni)
Correct Answer
A. Razmenu simetričnih ključevaExplanation
The correct answer is "Razmenu simetričnih ključeva" which translates to "Exchange of symmetric keys" in English. The Diffie-Hellman algorithm is used for securely exchanging symmetric keys between two parties over an insecure channel. It allows the two parties to agree on a shared secret key without actually transmitting the key itself. This shared key can then be used for symmetric encryption and decryption of messages between the parties.Rate this question:
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- 24.
Skup aktivnosti koje treba da se obezbede da neovlascena strana u komunikaciji ne dodje do poverljivih informacija naziva se
Correct Answer
poverljivostExplanation
The correct answer is "poverljivost." Poverljivost refers to the set of activities that need to be ensured in order to prevent unauthorized parties from accessing confidential information in communication. It involves safeguarding sensitive data and restricting access to authorized individuals only.Rate this question:
- 25.
KOji od sledecih algoritama moze da se koristi za digitalno potpisivanje
- A.
RSA
- B.
DES
- C.
AES
- D.
Diffie-Hellman
Correct Answer
A. RSAExplanation
RSA is the correct answer because it is an algorithm that can be used for digital signing. RSA is a widely used asymmetric encryption algorithm that involves the use of a public key for encryption and a private key for decryption. It can also be used for digital signatures, where the sender uses their private key to sign a message, and the receiver can verify the authenticity of the message using the sender's public key. DES and AES are symmetric encryption algorithms, while Diffie-Hellman is a key exchange algorithm, none of which are specifically designed for digital signing.Rate this question:
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- 26.
Ugradnjom podataka o vremenu slanja poruke u samu poruku
- A.
Može da se izvrši autentifikacija
- B.
Može da se izvrši autorizacija
- C.
Može da se otkrije neovlašćena izmena podataka
- D.
Može da se otkrije ponovno slanje iste poruke
Correct Answer
D. Može da se otkrije ponovno slanje iste porukeExplanation
By embedding the timestamp of the message in the message itself, it becomes possible to detect if the same message is being resent. This is because each time the message is sent, it will have a different timestamp, allowing for the detection of duplicate messages.Rate this question:
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- 27.
Supstitucija kod koje se vecina znakova menja istim sem onih najfrekventnijih koji mogu da se menjaju na vise nacina naziva se
Correct Answer
supstitucija homofonaExplanation
The given correct answer is "supstitucija homofona". This term refers to a substitution in which most of the characters are replaced with the same ones, except for the most frequent ones, which can be replaced in multiple ways. In other words, it is a type of substitution where the majority of characters are changed in a consistent manner, except for the most common characters that can be substituted in various ways.Rate this question:
- 28.
Heš funkcija je
- A.
Jednosmerna funkcija koja za ulaz proizvoljne konačne veličine daje izlaz fiksne dužine
- B.
Invertibilna funkcija koja za ulaz proizvoljne konačne veličine daje izlaz iste dužine kao što je ulaz
- C.
Jednosmerna funkcija koja za ulaz proizvoljne konačne veličine daje izlaz iste dužine kao što je ulaz
- D.
Invertibilna funkcija koja za ulaz proizvoljne konačne veličine daje izlaz fiksne dužine
Correct Answer
A. Jednosmerna funkcija koja za ulaz proizvoljne konačne veličine daje izlaz fiksne dužineExplanation
The correct answer is a one-way function that takes an input of arbitrary finite size and produces an output of fixed length. This means that the function is deterministic, meaning that given the same input, it will always produce the same output. Additionally, it is computationally infeasible to reverse-engineer the original input from the output, making it a one-way function. The fact that the output has a fixed length ensures that the function will always produce an output of the same size, regardless of the input size.Rate this question:
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- 29.
Sigurnost RSA algoritma lezi u
- A.
Slozenosti racunanja logaritama u konacnim poljima
- B.
Cinjenici da se koristi samo jedan kljuc
- C.
Slozenosti pronalazenja prostih faktora velikih brojeva
- D.
Slozenosti mnozenja dva velika prosta broja
Correct Answer
C. Slozenosti pronalazenja prostih faktora velikih brojevaExplanation
The security of the RSA algorithm lies in the complexity of finding the prime factors of large numbers. This is because the RSA algorithm is based on the difficulty of factoring large composite numbers into their prime factors. The larger the prime factors, the more secure the RSA encryption becomes. Therefore, the complexity of finding prime factors of large numbers is crucial for the security of the RSA algorithm.Rate this question:
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- 30.
Alisa zeli da posalje Bobu poruku m sifrovanu RSA algoritmom. Alisa sifruje poruku:
- A.
Bobovim javnim kljucem
- B.
Svojim javnim kljucem
- C.
Svojim privatnim kljucem
- D.
Bobovim privatnim kljucem
Correct Answer
A. Bobovim javnim kljucemExplanation
Alisa wants to send a message to Bob using the RSA algorithm. The RSA algorithm involves the use of public and private keys. In this case, Alisa encrypts the message using Bob's public key. This is the correct answer because when using RSA encryption, the sender encrypts the message with the recipient's public key, ensuring that only the recipient with the corresponding private key can decrypt and read the message.Rate this question:
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- 31.
Duzina kljuca koji je potreban za izracunavanje HMAC vrednosti je
- A.
Manji od 64 bita
- B.
Duzine poruke
- C.
Veci od 64 bita
- D.
Bar 128 bita
Correct Answer
A. Manji od 64 bitaExplanation
The correct answer is "Manji od 64 bita". HMAC (Hash-based Message Authentication Code) is a cryptographic hash function that requires a key for calculating the HMAC value. In this case, the length of the key needed for HMAC calculation is smaller than 64 bits.Rate this question:
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- 32.
Za digitalno potpisivanje koriste se
- A.
Simetricni kriptografski sistemi
- B.
Asimetricni kriptografski sistemi
- C.
Zavisi od izabranog sertifikacionog tela
- D.
Hibridni kriptografski sistemi
Correct Answer
B. Asimetricni kriptografski sistemiExplanation
Asimetricni kriptografski sistemi se koriste za digitalno potpisivanje. Ovi sistemi koriste dva ključa, javni i privatni, koji su međusobno povezani. Javni ključ se koristi za enkripciju podataka, dok se privatni ključ koristi za dekripciju. Kada se koristi za digitalno potpisivanje, privatni ključ se koristi za potpisivanje poruke, dok se javni ključ koristi za verifikaciju potpisa. Ova tehnika omogućava sigurnu razmenu informacija i potvrdu identiteta pošiljaoca.Rate this question:
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- 33.
Jednosmerna heš funkcija generise otisak duzine 160 bitova.Koliko mogucih ulaznih poruka generise heš vrednosti 0000....0001?
- A.
160
- B.
Beskonacno mnogo
- C.
Dve
- D.
Samo jedna
Correct Answer
B. Beskonacno mnogoExplanation
The given correct answer is "beskonacno mnogo". A hash function generates a fixed-length output regardless of the input size. In this case, the hash function generates a 160-bit output. Since the input message can vary in length, there are infinitely many possible input messages that can produce the same 160-bit hash value. Therefore, the hash function can generate an infinite number of input messages that result in the hash value "0000....0001".Rate this question:
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- 34.
Jednosmerna heš funkcija generiše otisak dužine 160 bitova. Koliko mogućih ulaznih poruka generiše heš vrednost 1?
- A.
Beskonacno mnogo poruka
- B.
Samo jedna
- C.
Ni jedna
- D.
Dve
Correct Answer
A. Beskonacno mnogo porukaExplanation
The given question asks how many possible input messages can generate a hash value of 1 using a one-way hash function that produces a 160-bit output. The correct answer is "beskonacno mnogo poruka" which means "infinitely many messages" in English. This is because hash functions are designed to have a high collision resistance, meaning that it is extremely unlikely for two different input messages to produce the same hash value. Therefore, there are an infinite number of possible input messages that can generate a hash value of 1.Rate this question:
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- 35.
Izabrati tacno tvrdjenje
- A.
Asimetrični algoritmi su sporiji od simetričnih
- B.
Brzine izvršenja asimetričnih i simetričnih algoritama su približno iste
- C.
Asimetrični algoritmi su brži od simetričnih
- D.
Odnos brzina asimetričnih i simetričnih algoritama zavise od konkretnih algoritama
Correct Answer
A. Asimetrični algoritmi su sporiji od simetričnihExplanation
The correct answer states that asymmetric algorithms are slower than symmetric algorithms. This means that when comparing the execution speeds of these two types of algorithms, asymmetric algorithms tend to be slower.Rate this question:
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- 36.
Aktivan napad kojim se neovlašćeno menjaju podaci, pristupna prava ili način funkcionisanja sistema je napad na:
- A.
Autentičnost
- B.
Poverljivost
- C.
Raspoloživost
- D.
Integritet
Correct Answer
D. IntegritetExplanation
This question is asking about the type of attack that involves unauthorized changes to data, access rights, or the functioning of a system. The correct answer is "Integritet." In the context of computer security, integrity refers to the accuracy, consistency, and trustworthiness of data. An attack on integrity would involve tampering with or modifying data in a way that compromises its reliability or validity.Rate this question:
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- 37.
Digitalni potpis je servis koji treba da obezbedi
- A.
Integritet i neporecivost
- B.
Autentifikaciju i autorizaciju
- C.
Poverljivost
- D.
Raspolozivost
Correct Answer
A. Integritet i neporecivostExplanation
A digital signature is a service that aims to provide integrity and non-repudiation. This means that it ensures the data has not been tampered with and verifies the identity of the sender, preventing them from denying their involvement. The digital signature also ensures the authenticity of the message, confirming that it was indeed sent by the claimed sender.Rate this question:
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- 38.
Kolizija kod heš funkcija označava pojavu da
- A.
Dve različite poruke daju istu heš vrednost
- B.
Da postoji poruka za koju ne može da se izračuna heš vrednost
- C.
Ista poruka može da da dve različite heš vrednosti
- D.
Da ako je dužina heš vrednosti N, postoji niz dužine N koji nije heš vrednost ni jedne poruke
Correct Answer
A. Dve različite poruke daju istu heš vrednostExplanation
The explanation for the given correct answer is that collision in hash functions refers to the occurrence of two different messages producing the same hash value. This means that two distinct inputs can result in the same output hash value, which can lead to potential conflicts or issues in certain applications that rely on unique hash values for data integrity and identification.Rate this question:
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- 39.
Jedna od nepozeljnih osobina generatora pseudoslucajnih brojeva je
- A.
Periodicnost
- B.
To sto ne mogu da se koriste za OTP sifru
- C.
To sto mu je za rad potrebna pocetna vrednost
- D.
To sto se u njihovom radu koriste komplikovane matematicke funkcije
Correct Answer
A. PeriodicnostExplanation
Periodicnost je jedna od nepoželjnih osobina generatora pseudoslučajnih brojeva. Periodicnost se odnosi na ponavljanje istih brojeva u nizu generisanih brojeva. U slučaju generatora pseudoslučajnih brojeva, periodičnost može dovesti do predvidljivosti i smanjiti sigurnost sistema koji se oslanjaju na generisane brojeve. Stoga, periodičnost je neželjena osobina generatora pseudoslučajnih brojeva.Rate this question:
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- 40.
Koliko parametara ima funkcija HMAC
- A.
(M,K)
- B.
(M,K,h(M))
- C.
(M,K,h(M),h(K))
- D.
(M)
Correct Answer
A. (M,K)Explanation
The correct answer is (M,K) because HMAC (Hash-based Message Authentication Code) is a cryptographic function that takes two parameters: the message (M) and the secret key (K). The function uses these parameters to generate a unique hash value that can be used to verify the integrity and authenticity of the message. The additional parameters in the other options are not necessary for the HMAC function.Rate this question:
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- 41.
DES algoritam ima
- A.
16 rundi
- B.
14 rundi
- C.
10 rundi
- D.
12 rundi
Correct Answer
A. 16 rundiExplanation
The correct answer is 16 rundi. The DES algorithm, which stands for Data Encryption Standard, consists of 16 rounds of encryption. Each round involves several operations, including permutation, substitution, and XOR operations, to transform the input data into the final encrypted output. These 16 rounds ensure a high level of security and make it difficult for unauthorized individuals to decrypt the encrypted data without the proper key.Rate this question:
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- 42.
Sta se kod steganografije krije?
- A.
Cinjenica da se prenosi poruka
- B.
Komunikacija
- C.
Steganografski kanal
- D.
Steganografski medijum
Correct Answer
A. Cinjenica da se prenosi porukaExplanation
The correct answer is "cinjenica da se prenosi poruka" which translates to "the fact that a message is being transmitted" in English. In steganography, the main purpose is to hide the existence of a message within a carrier medium. The answer suggests that what is being concealed in steganography is the fact that a message is being transmitted, rather than the actual content of the message itself. This highlights the covert nature of steganography, where the goal is to hide the communication rather than encrypting or protecting the content of the message.Rate this question:
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- 43.
DES algoritam je
- A.
Blokovski algoritam Fejstelovog tipa
- B.
Iterativni blokovski algoritam
- C.
Algoritam koji se ne koristi za sifrovanje
- D.
Sekvencijalni algoritam
Correct Answer
A. Blokovski algoritam Fejstelovog tipaExplanation
The given correct answer states that DES algorithm is a "blokovski algoritam Fejstelovog tipa" which translates to "block cipher algorithm of the Feistel type" in English. This means that DES is a type of symmetric encryption algorithm that operates on fixed-size blocks of data using a Feistel network structure. It divides the input into blocks and applies a series of transformations to each block to produce the encrypted output. Therefore, the answer correctly identifies DES as a block cipher algorithm of the Feistel type.Rate this question:
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- 44.
Koje su od navedenih sifri poligramske
- A.
Hilova
- B.
Vernamova
- C.
Afina
- D.
Plejferova
- E.
Cezarova
- F.
Prosta supstitucija
Correct Answer(s)
A. Hilova
D. PlejferovaExplanation
The correct answer is "Hilova, Plejferova." These are the names of different types of polygraphic ciphers. "Hilova" refers to the Hill cipher, a polygraphic substitution cipher that uses linear algebra to encrypt and decrypt messages. "Plejferova" refers to the Playfair cipher, another type of polygraphic substitution cipher that uses a 5x5 grid of letters to encrypt and decrypt messages.Rate this question:
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- 45.
Za ECB i CBC rezime rada vazi:
- A.
U ECB rezimu isti blok istim kljucem uvek daje isti sifrat, dok u CBC to ne mora da bude slucaj
- B.
I u CBC i u ECB rezimu isti blok istim kljucem uvek daje razlicit sifrat
- C.
U CBC rezimu isti blok istim kljucem uvek daje isti sifrat, dok u ECB to ne mora da bude slucaj
- D.
I u CBC i u ECB rezimu isti blok istim kljucem uvek daje isti sifrat
Correct Answer
A. U ECB rezimu isti blok istim kljucem uvek daje isti sifrat, dok u CBC to ne mora da bude slucajExplanation
In ECB mode, the same block with the same key will always produce the same ciphertext. However, in CBC mode, this may not be the case. In CBC mode, each block of plaintext is XORed with the previous ciphertext block before encryption, which introduces randomness and makes the ciphertext different even if the same block and key are used. This makes CBC mode more secure than ECB mode, as it prevents patterns in the plaintext from being preserved in the ciphertext.Rate this question:
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- 46.
Sifrarski sistem ako ne moze da bude razbijen ni uz primenu neogranicenih resursa ljudstva i vremena je
Correct Answer
bezuslovno siguranExplanation
The given statement states that if a cipher system cannot be broken even with unlimited resources of manpower and time, then it is unconditionally secure. This means that the system is completely secure and cannot be decrypted or compromised by any means, ensuring the confidentiality and integrity of the information.Rate this question:
- 47.
ByteSub, ShiftRow,MaxColumn,AddRoundKey su operacije koje se vezuju za
- A.
AES algoritam
- B.
Trostruki DES algoritam
- C.
DES algoritam
- D.
AS/1 algoritam
Correct Answer
A. AES algoritamExplanation
The given correct answer is AES algorithm. ByteSub, ShiftRow, MaxColumn, and AddRoundKey are operations that are associated with the AES algorithm. AES (Advanced Encryption Standard) is a widely used symmetric encryption algorithm that is used to secure sensitive data. The ByteSub operation involves substituting each byte in the state matrix with a corresponding byte from the S-box. The ShiftRow operation involves shifting the rows of the state matrix. The MaxColumn operation involves selecting the maximum value from each column in the state matrix. The AddRoundKey operation involves XORing the state matrix with a round key. Together, these operations form the basis of the AES algorithm.Rate this question:
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- 48.
AES algoritam je
- A.
Algoritam koji se ne koristi za sifrovanje
- B.
Blokovski algoritam Fejstelovog tipa
- C.
Sekevencijalni algoritam
- D.
Iterativni blokovski algoritam
Correct Answer
D. Iterativni blokovski algoritamExplanation
The correct answer is "iterativni blokovski algoritam". The explanation is that the AES algorithm is an iterative block cipher algorithm. It operates on fixed-size blocks of data and uses multiple rounds of encryption to transform the input data into ciphertext. Each round consists of several operations, including substitution, permutation, and mixing of the data. This iterative process increases the security of the algorithm and makes it resistant to various cryptographic attacks.Rate this question:
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- 49.
Kod blokovskog algoritma, po pravilu
- A.
Odnos duzina bloka otvorenog teksta i bloka sifrata zavisi od algoritama
- B.
Blok sifrata je iste duzine kao blok otvorenog teksta
- C.
Blok sifrata je manje duzine od bloka otvorenog teksta
- D.
Blok sifrata je vece duzine od bloka otvorenog teksta
Correct Answer
B. Blok sifrata je iste duzine kao blok otvorenog tekstaExplanation
The correct answer is "blok sifrata je iste duzine kao blok otvorenog teksta" because in block cipher algorithms, the length of the ciphertext block is the same as the length of the plaintext block. This means that each block of plaintext is encrypted into a block of ciphertext with the same length.Rate this question:
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- 50.
Aktivan napad kojim se neovlasceno menjaju podaci pristupna prava ili nacin funkcionisanja sistema je napad na
Correct Answer
integritet podatakaExplanation
This answer is correct because the given statement describes an active attack where unauthorized changes are made to access rights or the functioning of a system. Such an attack compromises the integrity of the data, as it manipulates or alters the data in an unauthorized manner, potentially leading to loss or corruption of information.Rate this question:
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Mar 21, 2023Quiz Edited by
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Jan 25, 2017Quiz Created by
Hanibani1823