source_dataset stringclasses 1
value | question stringlengths 6 1.87k | choices stringlengths 20 1.02k | answer stringclasses 4
values | rationale float64 | documents stringlengths 1.01k 5.9k |
|---|---|---|---|---|---|
epfl-collab | Tick the \emph{false} assertion concerning WPA-TKIP. | ['WPA-TKIP avoids replay attacks using a counter.', 'WPA-TKIP provides much more confidentiality than WEP.', 'WPA-TKIP uses a fixed RC4 key.', "WPA-TKIP doesn't protect well the integrity of the messages."] | C | null | Document 1:::
KRACK
KRACK ("Key Reinstallation Attack") is a replay attack (a type of exploitable flaw) on the Wi-Fi Protected Access protocol that secures Wi-Fi connections. It was discovered in 2016 by the Belgian researchers Mathy Vanhoef and Frank Piessens of the University of Leuven. Vanhoef's research group publi... |
epfl-collab | Tick the \emph{correct} assertion. In ElGamal $\ldots$ | ['the encryption algorithm is deterministic.', 'the key recovery problem is equivalent to the Computational Diffie Hellman problem.', 'the decryption problem can be hard even if the discrete logarithm is easy to compute in the underlying group.', 'the size of the ciphertext is always bigger than the size of the corresp... | D | null | Document 1:::
Decision Linear assumption
The Decision Linear (DLIN) assumption is a computational hardness assumption used in elliptic curve cryptography. In particular, the DLIN assumption is useful in settings where the decisional Diffie–Hellman assumption does not hold (as is often the case in pairing-based cryptogr... |
epfl-collab | One-time pad ... | ['pads the message at least once before encryption.', 'never uses a key $K$ which is picked from a uniform distribution.', 'uses an invertible group operation such as ``$\\oplus$" for encryption.', 'allows an efficient key management.'] | C | null | Document 1:::
Blinding (cryptography)
The one-time pad (OTP) is an application of blinding to the secure communication problem, by its very nature. Alice would like to send a message to Bob secretly, however all of their communication can be read by Oscar. Therefore, Alice sends the message after blinding it with a sec... |
epfl-collab | The Merkle-D{\aa}mgard construction is | ['a method which constructs a compression function from a block cipher.', 'a method which constructs a block cipher function from a hash function.', 'a method which iterates a compression function to obtain a hash function.', 'a method which iterates a hash function to obtain a compression function.'] | C | null | Document 1:::
Ralph Merkle puzzle cryptographic system
In cryptography, Merkle's Puzzles is an early construction for a public-key cryptosystem, a protocol devised by Ralph Merkle in 1974 and published in 1978. It allows two parties to agree on a shared secret by exchanging messages, even if they have no secrets in com... |
epfl-collab | The Fermat Test outputs `maybe prime' with probability which may be high given though $n$ is composite when ... | ['$n$ is a Fermat number.', '$n$ is an even composite.', '$n$ is the multiplication of two primes.', '$n$ is a Carmichael number.'] | D | null | Document 1:::
Fermat pseudoprime
Fermat's little theorem states that if p is prime and a is coprime to p, then ap−1 − 1 is divisible by p. For an integer a > 1, if a composite integer x divides ax−1 − 1, then x is called a Fermat pseudoprime to base a.: Def. 3.32 In other words, a composite integer is a Fermat pseudopr... |
epfl-collab | What should the minimal length of the output of a hash function be to provide security against \emph{collision attacks} of $2^{256}?$ | ['$512$ bits.', '$2^{512}$ bits.', '$2^{256}$ bits.', '$256$ bits.'] | A | null | Document 1:::
Minimal perfect hash function
For frequently changing S dynamic perfect hash functions may be used at the cost of additional space. The space requirement to store the perfect hash function is in O(n). The important performance parameters for perfect hash functions are the evaluation time, which should be ... |
epfl-collab | Let $G$ be a group generated by $g$. What is the discrete logarithm problem? | ["find $x,x'$ such that $g^x=g^{x'}$ and $x\\ne x'$.", 'find $y$ such that $g^x=y$ for a given $x$.', 'find $x$ such that $g^x=y$ for a given $y$.', 'find $x,y$ such that $g^x=y$.'] | C | null | Document 1:::
Discrete log problem
Let G be any group. Denote its group operation by multiplication and its identity element by 1. Let b be any element of G. For any positive integer k, the expression bk denotes the product of b with itself k times: b k = b ⋅ b ⋯ b ⏟ k factors .
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Discrete Logarithm
In math... |
epfl-collab | Bluetooth is \dots | ['\\emph{not} designed to transmit data.', 'first introduced by vikings.', 'a short-range wireless technology.', 'a long-range wireless technology.'] | C | null | Document 1:::
Bluetooth Basic Rate/Enhanced Data Rate
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limited to 2.5 milliwatts, ... |
epfl-collab | Tick the \emph{false} answer. In a group, the operation\dots | ['is associative.', 'has a neutral element.', 'is commutative', 'associates an inverse to each value.'] | C | null | Document 1:::
False (logic)
In logic, false or untrue is the state of possessing negative truth value and is a nullary logical connective. In a truth-functional system of propositional logic, it is one of two postulated truth values, along with its negation, truth. Usual notations of the false are 0 (especially in Bool... |
epfl-collab | Consider a public-key cryptosystem. Let $K_p$, $K_s$, $X$, and $Y$ be respectively the public key, private key, plaintext and ciphertext. Which assertion is \emph{always true}? | ['$Dec_{K_s}(Enc_{K_p}(X))=X$', '$Enc_{K_p}(Dec_{K_s}(X))=X$', '$Dec_{K_p}(Enc_{K_s}(Y))=Y$', '$Enc_{K_s}(Dec_{K_p}(Y))=Y$'] | A | null | Document 1:::
Kerckhoffs's principle
Kerckhoffs's principle (also called Kerckhoffs's desideratum, assumption, axiom, doctrine or law) of cryptography was stated by Dutch-born cryptographer Auguste Kerckhoffs in the 19th century. The principle holds that a cryptosystem should be secure, even if everything about the sys... |
epfl-collab | Select the \emph{incorrect} statement. Euler Theorem | ['allows us to prove that RSA decryption works.', 'is a generalization of Little Fermat Theorem.', 'gives the basis for polynomial time factoring.', 'states that any $x \\in \\{0, \\dots, N-1 \\}$ and any $k$, we have $x^{k\\varphi(N)+1}=x \\pmod N$, where $N=pq$ for $p$,$q$ distinct primes.'] | C | null | Document 1:::
Euler calculus
Euler calculus is a methodology from applied algebraic topology and integral geometry that integrates constructible functions and more recently definable functions by integrating with respect to the Euler characteristic as a finitely-additive measure. In the presence of a metric, it can be ... |
epfl-collab | Tick the \textit{correct} assertion. | ['The set of quadratic residues in $\\mathbb{Z}_n$ is a field.', 'In a finite field $K$, every element has exactly two square roots.', 'In a finite field $K$, 1 has exactly one square roots and it is 1.', 'An element can have more than two square roots in $\\mathbb{Z}_n$.'] | D | null | Document 1:::
Test assertion
In computer software testing, a test assertion is an expression which encapsulates some testable logic specified about a target under test. The expression is formally presented as an assertion, along with some form of identifier, to help testers and engineers ensure that tests of the target... |
epfl-collab | Let $p$ be a prime number and $n$ be an integer. What is the order of $\mathrm{GF}(p^n)$? | ['$1-p^n$', '$p^n-1$', '$p^n$', '$p^{n-1}$'] | C | null | Document 1:::
Number Field Sieve
In number theory, the general number field sieve (GNFS) is the most efficient classical algorithm known for factoring integers larger than 10100. Heuristically, its complexity for factoring an integer n (consisting of ⌊log2 n⌋ + 1 bits) is of the form exp ( ( ( 64 / 9 ) 1 / 3 + o ( 1 ... |
epfl-collab | Under which condition is an element $x\in \mathbb{Z}_n$ invertible? | ['$\\mathsf{gcd}(x,n) \\ne 1$.', '$\\mathsf{gcd}(x,n) = 1$.', '$\\mathsf{gcd}(x,\\varphi (n)) = 1$.', '$\\mathsf{gcd}(x,n-1) = 1$.'] | B | null | Document 1:::
Invertible element
An element is invertible under an operation if it has a left inverse and a right inverse. In the common case where the operation is associative, the left and right inverse of an element are equal and unique. Indeed, if l and r are respectively a left inverse and a right inverse of x, th... |
epfl-collab | If Alice receives a message proven to be coming from Bob, we say that the message is\dots | ['fresh', 'correct', 'authenticated', 'confidential'] | C | null | Document 1:::
Security protocol notation
In cryptography, security (engineering) protocol notation, also known as protocol narrations and Alice & Bob notation, is a way of expressing a protocol of correspondence between entities of a dynamic system, such as a computer network. In the context of a formal model, it allow... |
epfl-collab | Which cryptographic primitive(s) is (are) used in S/Key - OTP ? | ['Only encryption and a MAC algorithm', 'Only a MAC', 'Only a hash function', 'Only encryption and a hash function'] | C | null | Document 1:::
Cryptographic primitive
Cryptographic primitives are well-established, low-level cryptographic algorithms that are frequently used to build cryptographic protocols for computer security systems. These routines include, but are not limited to, one-way hash functions and encryption functions.
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... |
epfl-collab | Let $(e,N)$ be the public parameters of the RSA cryptosystem. What is the advantage of taking a \emph{small} value for $e$? | ['The complexity of the encryption step is smaller.', 'The complexity of the parameters generation is smaller.', 'The whole system is stronger against several attacks.', 'The complexity of the decryption step is smaller.'] | A | null | Document 1:::
RSA Cryptosystem
An RSA user creates and publishes a public key based on two large prime numbers, along with an auxiliary value. The prime numbers are kept secret. Messages can be encrypted by anyone, via the public key, but can only be decoded by someone who knows the prime numbers.The security of RSA re... |
epfl-collab | Let $p$ and $q$ be two distinct prime numbers and let $x \in \mathbf{Z}_{pq}^*$. Which of the following assertion is always true in $\mathbf{Z}_{pq}^*$? | ['$x^{(p-1)(q-1)} = 1$', '$x^{pq} = 1$', '$x^{p} = 1$', '$x^{q} = 1$'] | A | null | Document 1:::
Prime element
Interest in prime elements comes from the fundamental theorem of arithmetic, which asserts that each nonzero integer can be written in essentially only one way as 1 or −1 multiplied by a product of positive prime numbers. This led to the study of unique factorization domains, which generaliz... |
epfl-collab | Let $h$ be a cryptographic hash function based on the Merkle-Damg{\aa}rd scheme. The Merkle-Damg{\aa}rd Theorem states that\dots | ['\\dots if the compression function is collision-resistant, then $h$ is collision-resistant.', '\\dots $h$ is resistant to a first preimage attack.', '\\dots if $h$ is collision-resistant, then the compression function is collision-resistant.', '\\dots $h$ is collision-resistant.'] | A | null | Document 1:::
Hash chain
A hash chain is a successive application of a cryptographic hash function h {\displaystyle h} to a string x {\displaystyle x} . For example, h ( h ( h ( h ( x ) ) ) ) {\displaystyle h(h(h(h(x))))} gives a hash chain of length 4, often denoted h 4 ( x ) {\displaystyle h^{4}(x)}
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Min... |
epfl-collab | $\mathbb{Z}_{37}^*$ denotes ... | ['a field.', 'a multiplicative group.', 'a ring.', 'an additive group.'] | B | null | Document 1:::
Z* theorem
In mathematics, George Glauberman's Z* theorem is stated as follows: Z* theorem: Let G be a finite group, with O(G) being its maximal normal subgroup of odd order. If T is a Sylow 2-subgroup of G containing an involution not conjugate in G to any other element of T, then the involution lies in ... |
epfl-collab | Visual cryptography is a nice visual application of \ldots | ['\\ldots ROT13.', '\\ldots the Caesar cipher.', '\\ldots the Vernam cipher.', '\\ldots the Vigen\\`ere cipher.'] | C | null | Document 1:::
Visual cryptography
Visual cryptography is a cryptographic technique which allows visual information (pictures, text, etc.) to be encrypted in such a way that the decrypted information appears as a visual image. One of the best-known techniques has been credited to Moni Naor and Adi Shamir, who developed ... |
epfl-collab | Select the \emph{incorrect} statement. | ['The order of an element is always multiple of the order of its group.', 'An ideal $I$ of commutative ring $R$ is a subgroup closed under multiplication by all elements of $R$.', 'Any element of order $\\varphi(n)$ is a generator of $\\mathbb{Z}_n^*$.', 'Given a prime $p$, we have $a^{p} = a$ for every $a \\in \\mathb... | A | null | Document 1:::
Uncertain inference
Rather than retrieving a document that exactly matches the query we should rank the documents based on their plausibility in regards to that query. Since d and q are both generated by users, they are error prone; thus d → q {\displaystyle d\to q} is uncertain. This will affect the plau... |
epfl-collab | Which one of these is a closed set? | ['$\\mathbb{Z}$ with the addition.', '$\\mathbb{Z}^\\star$ with the addition.', '$\\mathbb{Z}^\\star$ with the substaction.', '$\\mathbb{Z}-\\{0\\}$ with the division.'] | A | null | Document 1:::
Closure (mathematics)
Let S be a set equipped with one or several methods for producing elements of S from other elements of S. A subset X of S is said to be closed under these methods, if, when all input elements are in X, then all possible results are also in X. Sometimes, one may also say that X has th... |
epfl-collab | Tick the \textbf{incorrect} assertion. | ['ECDSA uses elliptic curves.', 'An ECDSA signature consists in the message and a pair of elements in $\\mathbb{Z}_n$.', 'Subtraction is hard to perform on an elliptic curve.', 'PKCS\\#1v1.5 uses plain RSA as an internal routine.'] | C | null | Document 1:::
Talk:Fibonacci sequence
Well spotted (and sorry for reverting). TheMathCat (talk) 15:43, 15 September 2022 (UTC) (edit conflict) OK, you reverted me just before my self revert. On the table on the right, there is a large vertical space between the first index and the first value (1).
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Charset... |
epfl-collab | Select the \emph{correct} statement. The Plain RSA Signature scheme | ['has modulus $N=p^2$.', 'has a secret modulus $d$ to be selected so that $e+d = 0 \\pmod{\\varphi(N)}$.', 'has public modulus $e$ to be selected so that $\\text{gcd} (e, \\varphi(N)) > 1$.', 'allows us to pick a fixed public key exponent like $e=3$ or $e=2^{16}+1$.'] | D | null | Document 1:::
Probabilistic signature scheme
Probabilistic Signature Scheme (PSS) is a cryptographic signature scheme designed by Mihir Bellare and Phillip Rogaway.RSA-PSS is an adaptation of their work and is standardized as part of PKCS#1 v2.1. In general, RSA-PSS should be used as a replacement for RSA-PKCS#1 v1.5.
... |
epfl-collab | Which of the following is an element of $\mathbb{Z}_{60}^*$? | ['49', '30', '26', '21'] | A | null | Document 1:::
Signed-digit representation
A Prüfer group is the quotient group Z ( b ∞ ) = Z / Z {\displaystyle \mathbb {Z} (b^{\infty })=\mathbb {Z} /\mathbb {Z} } of the integers and the b {\displaystyle b} -adic rationals. The set of all signed-digit representations of the Prüfer group is given by the Kleene star D... |
epfl-collab | Which of the following algorithms is \emph{not} a hash function? | ['SHA-1', 'MD4', 'RC4', 'MD5'] | C | null | Document 1:::
Secure Hash Algorithms
The Secure Hash Algorithms are a family of cryptographic hash functions published by the National Institute of Standards and Technology (NIST) as a U.S. Federal Information Processing Standard (FIPS), including: SHA-0: A retronym applied to the original version of the 160-bit hash f... |
epfl-collab | Select the \emph{correct} answer. | ['The dictionary attack needs no precomputation.', 'The dictionary attack has a memory complexity of order 1.', 'The success probability of the dictionary attack depends on the size of the dictionary.', 'The multi-target dictionary attack needs no precomputation.'] | C | null | Document 1:::
Multiple choice questions
Multiple choice (MC), objective response or MCQ (for multiple choice question) is a form of an objective assessment in which respondents are asked to select only correct answers from the choices offered as a list. The multiple choice format is most frequently used in educational ... |
epfl-collab | Tick the \emph{false} assertion. Given a ring $R$, $R^\star$ is\ldots | ['the set of units.', '$R-\\{0\\}$.', 'a group.', 'the set of invertible elements in $R$.'] | B | null | Document 1:::
Boolean rings
In mathematics, a Boolean ring R is a ring for which x2 = x for all x in R, that is, a ring that consists only of idempotent elements. An example is the ring of integers modulo 2. Every Boolean ring gives rise to a Boolean algebra, with ring multiplication corresponding to conjunction or mee... |
epfl-collab | Select the \emph{incorrect} statement. Bluetooth is | ['a short-range wireless technology.', 'able to transmit 1Mbit/sec in 10m distance.', 'a standard for RFID tags.', 'designed both for data and voice transmission.'] | C | null | Document 1:::
Bluetooth Basic Rate/Enhanced Data Rate
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limited to 2.5 milliwatts, ... |
epfl-collab | Which cipher is AES? | ['RC5', 'SAFER', 'BLOWFISH', 'RIJNDAEL'] | D | null | Document 1:::
Cipher
In 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... |
epfl-collab | Which of the following algorithms is a stream cipher? | ['FOX', 'IDEA', 'RC4', 'AES'] | C | null | Document 1:::
Cipher
Without knowledge of the key, it should be extremely difficult, if not impossible, to decrypt the resulting ciphertext into readable plaintext. Most modern ciphers can be categorized in several ways By whether they work on blocks of symbols usually of a fixed size (block ciphers), or on a continuou... |
epfl-collab | Consider a public key cryptosystem. The channel used to transmit the public key has to be\dots | ['\\dots authenticated.', '\\dots authenticated and confidential.', '\\dots encrypted.', '\\dots confidential.'] | A | null | Document 1:::
Threshold cryptosystem
A threshold cryptosystem, the basis for the field of threshold cryptography, is a cryptosystem that protects information by encrypting it and distributing it among a cluster of fault-tolerant computers. The message is encrypted using a public key, and the corresponding private key i... |
epfl-collab | KEM/DEM refers to\dots | ['a hash function.', 'an encryption scheme.', 'a digital signature scheme.', 'a commitment scheme.'] | B | null | Document 1:::
Dot-decimal notation
Dot-decimal notation is a presentation format for numerical data. It consists of a string of decimal numbers, using the full stop (dot) as a separation character.A common use of dot-decimal notation is in information technology where it is a method of writing numbers in octet-grouped ... |
epfl-collab | Tick the \textbf{false} statement. | ['The cardinality of $E_{a,b}(\\mathsf{GF}(q))$ is bounded by $q+1+2\\sqrt{q}$.', 'In $(\\mathsf{GF}(2^k))$, we have $\\mathsf{Tr}(a+b)=\\mathsf{Tr}(a)+\\mathsf{Tr}(b)$.', 'Two Elliptic curves cannot have the same $j$-invariant.', '$E_{a,b}$ is non-singular if $4a^3+27b^2 \\neq 0$ over a finite field of characteristic ... | C | null | Document 1:::
False (logic)
In logic, false or untrue is the state of possessing negative truth value and is a nullary logical connective. In a truth-functional system of propositional logic, it is one of two postulated truth values, along with its negation, truth. Usual notations of the false are 0 (especially in Bool... |
epfl-collab | Select \emph{incorrect} statement. The brute force technique against a cipher with key $256$ bits is | ['impossible since the number of possible keys is too high $2^{256} \\approx 10^{77}$.', 'feasible using all clusters at EPFL.', "impossible in future even if we consider Moore's law.", 'impossible even if we can compute without burning an energy.'] | B | null | Document 1:::
Brute force attack
In cryptography, a brute-force attack consists of an attacker submitting many passwords or passphrases with the hope of eventually guessing correctly. The attacker systematically checks all possible passwords and passphrases until the correct one is found. Alternatively, the attacker ca... |
epfl-collab | Select the \emph{weakest} algorithm. | ['A5/1', 'A5/4', 'A5/3', 'A5/2'] | D | null | Document 1:::
Selection problem
In computer science, a selection algorithm is an algorithm for finding the k {\displaystyle k} th smallest value in a collection of ordered values, such as numbers. The value that it finds is called the k {\displaystyle k} th order statistic. Selection includes as special cases the probl... |
epfl-collab | Tick the \textit{incorrect} assertion. | ['HMAC is a message authentication code based on a hash function.', 'GCM is a blockcipher mode of operation that provides both confidentiality and authenticity for messages.', 'Plain CBCMAC resists forgery attacks.', 'A message authentication scheme that resists a chosen message forgery attack will also resist a known ... | C | null | Document 1:::
False position
In mathematics, the regula falsi, method of false position, or false position method is a very old method for solving an equation with one unknown; this method, in modified form, is still in use. In simple terms, the method is the trial and error technique of using test ("false") values for... |
epfl-collab | The Moore law | ['has no relevance for cryptography since it only considers speed of computation', 'says that CPU speed doubles every 18 months', 'states that anything that can go wrong will', 'implies the key size is doubled every every 18 months to preserve confidentiality'] | B | null | Document 1:::
Computational power
Moore's law is the observation that the number of transistors in an integrated circuit (IC) doubles about every two years. Moore's law is an observation and projection of a historical trend. Rather than a law of physics, it is an empirical relationship linked to gains from experience i... |
epfl-collab | Select the \emph{incorrect} statement. The Bluetooth project aims for | ['low security.', 'low power.', 'low complexity.', 'low cost.'] | A | null | Document 1:::
Bluetooth Basic Rate/Enhanced Data Rate
It is mainly used as an alternative to wire connections, to exchange files between nearby portable devices and connect cell phones and music players with wireless headphones. Bluetooth is managed by the Bluetooth Special Interest Group (SIG), which has more than 35,... |
epfl-collab | Tick the \emph{false} assertion. The ambiguity issue in the decryption algorithm of the Rabin cryptosystem can be solved by\dots | ['encrypting the message twice.', 'ensuring that the other possible plaintexts make no sense.', 'appending some integrity checks to the message before encryption.', 'encrypting the message appended to itself.'] | A | null | Document 1:::
False (logic)
In logic, false or untrue is the state of possessing negative truth value and is a nullary logical connective. In a truth-functional system of propositional logic, it is one of two postulated truth values, along with its negation, truth. Usual notations of the false are 0 (especially in Bool... |
epfl-collab | What is the order of $2^{124}$ in $(\mathbb{Z}_{2^{128}},+)$? | ['$\\varphi(2^{128})$.', '8.', '16.', '124.'] | C | null | Document 1:::
Multiplicative order
In number theory, given a positive integer n and an integer a coprime to n, the multiplicative order of a modulo n is the smallest positive integer k such that a k ≡ 1 ( mod n ) {\textstyle a^{k}\ \equiv \ 1{\pmod {n}}} .In other words, the multiplicative order of a modulo n is the or... |
epfl-collab | Which problem in communication is \emph{not} treated by cryptography? | ['confidentiality', 'authenthication', 'integrity', 'data transmission'] | D | null | Document 1:::
Non-commutative cryptography
Non-commutative cryptography is the area of cryptology where the cryptographic primitives, methods and systems are based on algebraic structures like semigroups, groups and rings which are non-commutative. One of the earliest applications of a non-commutative algebraic structu... |
epfl-collab | What are the complexities for the single-target dictionary attacks, when there are $N$ keys? | ['Preprocessing: $N$, Memory: $1$, Time: $N$', 'Preprocessing: $0$, Memory: $1$, Time: $\\sqrt{N}$', 'Preprocessing: $1$, Memory: $N$, Time: $N$', 'Preprocessing: $N$, Memory: $N$, Time: 1'] | D | null | Document 1:::
Correlation attack
Third order correlations and higher can be defined in this way. Higher-order correlation attacks can be more powerful than single-order correlation attacks, however, this effect is subject to a "law of limiting returns". The table below shows a measure of the computational cost for vari... |
epfl-collab | Tick the \emph{incorrect} assertion. The Diffie-Hellman key agreement protocol \ldots | ['is easy to break when working on the group $\\mathbf{Z}_{n}$.', 'requires the hardness of the Discrete Logarithm problem.', 'uses ElGamal encryption in order to establish the key.', 'allows two participants to set up a key so that they can communicate securely.'] | C | null | Document 1:::
Elliptic-curve Diffie-Hellman
Elliptic-curve Diffie–Hellman (ECDH) is a key agreement protocol that allows two parties, each having an elliptic-curve public–private key pair, to establish a shared secret over an insecure channel. This shared secret may be directly used as a key, or to derive another key. ... |
epfl-collab | Which of these components was not part of the Enigma machine? | ['A pseudo-random number generator', 'A plugboard with a wire connection', 'A Rotor', 'A reflector'] | A | null | Document 1:::
Rotor cipher machine
In cryptography, a rotor machine is an electro-mechanical stream cipher device used for encrypting and decrypting messages. Rotor machines were the cryptographic state-of-the-art for much of the 20th century; they were in widespread use in the 1920s–1970s. The most famous example is t... |
epfl-collab | Consider password-based access control. Tick the \textit{incorrect} assertion. | ['Increasing the delay between authentication attempts can protect from online attacks.', 'Double hashing the password can help avoid the problems related to low-entropy passwords.', 'Blocking the access after 10 unsuccessful authentication attempts can protect from online attacks.', 'Salt can be used to thwart multi-t... | B | null | Document 1:::
Logical access control
In computers, logical access controls are tools and protocols used for identification, authentication, authorization, and accountability in computer information systems. Logical access is often needed for remote access of hardware and is often contrasted with the term "physical acce... |
epfl-collab | Select the \emph{incorrect} statement. In ElGamal signature | ['the public key is $K_p = y = g^x$, where $x$ is the secret key.', 'public parameters are a prime number $p$ and a generator $g$ of $\\mathbb{Z}_p^*$.', 'requires a secure channel to transfer the signature.', 'verification checks whether $y^rr^s=g^{H(M)}$ for signature $\\sigma=(r, s)$ of the message $M$ and the hash ... | C | null | Document 1:::
ElGamal cryptosystem
In cryptography, the 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 ... |
epfl-collab | You are given the task of choosing the parameters of a hash function. What value of the output will you recommend in order to be minimal and secure against second preimage attacks? | ['40 bits', '80 bits', '320 bits', '160 bits'] | D | null | Document 1:::
Minimal perfect hash function
For frequently changing S dynamic perfect hash functions may be used at the cost of additional space. The space requirement to store the perfect hash function is in O(n). The important performance parameters for perfect hash functions are the evaluation time, which should be ... |
epfl-collab | $\mathrm{GF}(2^k)$ is represented by the set of\dots | ['polynomials of degree at most $k-1$ with coefficients in $\\mathbb{Z}_k$.', 'polynomials of degree at most $2$ with coefficients in $\\mathbb{Z}_k$.', 'polynomials of degree at most $k-1$ with binary coefficients.', 'polynomials of degree at most $2^k$ with coefficients in $\\mathbb{Z}$.'] | C | null | Document 1:::
Binary field
GF(2) (also denoted F 2 {\displaystyle \mathbb {F} _{2}} , Z/2Z or Z / 2 Z {\displaystyle \mathbb {Z} /2\mathbb {Z} } ) is the finite field of two elements (GF is the initialism of Galois field, another name for finite fields). Notations Z2 and Z 2 {\displaystyle \mathbb {Z} _{2}} may be enco... |
epfl-collab | Thick the \emph{incorrect} assertion. | ['SAS-based cryptography always requires the SAS to be collision-resistant.', 'One can obtain a secure channel from a narrowband authenticated channel using SAS-based cryptography.', 'The goal of SAS-based cryptography is to reduce the length of the string that has to be authenticated.', 'One way to authenticate a SAS ... | A | null | Document 1:::
False (logic)
In logic, false or untrue is the state of possessing negative truth value and is a nullary logical connective. In a truth-functional system of propositional logic, it is one of two postulated truth values, along with its negation, truth. Usual notations of the false are 0 (especially in Bool... |
epfl-collab | According to the Kerckhoffs Principle: | ['The security of the cryptosystem should \\emph{not} rely on the secrecy of the cryptosystem itself.', 'The internal design of a cryptosystem should be public.', 'If there is a single security hole in a cryptosystem, somebody will discover it.', 'The internal design of a cryptosystem should \\emph{not} be public.'] | A | null | Document 1:::
Kerckhoffs's principle
Kerckhoffs's principle (also called Kerckhoffs's desideratum, assumption, axiom, doctrine or law) of cryptography was stated by Dutch-born cryptographer Auguste Kerckhoffs in the 19th century. The principle holds that a cryptosystem should be secure, even if everything about the sys... |
epfl-collab | KEM \dots | ['stands for Keyless Encryption Mechanism.', 'is a symmetric-key algorithm.', 'is a public-key algorithm.', 'is a Korean encryption mechanism.'] | C | null | Document 1:::
Dot plot (statistics)
A dot chart or dot plot is a statistical chart consisting of data points plotted on a fairly simple scale, typically using filled in circles. There are two common, yet very different, versions of the dot chart. The first has been used in hand-drawn (pre-computer era) graphs to depict... |
epfl-collab | Tick the \emph{false} assertion. Two-keys triple DES\dots | ['is vulnerable to a certain variant of a meet-in-the-middle attacks.', 'is less secure than AES.', 'is as secure as a block cipher using a key twice longer.', 'is more secure than double encryption.'] | C | null | Document 1:::
False (logic)
In logic, false or untrue is the state of possessing negative truth value and is a nullary logical connective. In a truth-functional system of propositional logic, it is one of two postulated truth values, along with its negation, truth. Usual notations of the false are 0 (especially in Bool... |
epfl-collab | Tick the \textbf{true} statement regarding $\mathbb{Z}_p^*$, where $p$ is an arbitrary prime number. | ['For any $x \\in \\mathbb{Z}_p^*$ we have $x^{p}=1 \\pmod p$', 'It is a group of prime order when $p>3$.', 'It is isomorphic to $\\mathbb{Z}_n^*$ for all $n >0$.', 'It has $\\varphi(p-1)$ generators.'] | D | null | Document 1:::
Supersingular prime (algebraic number theory)
In algebraic number theory, a supersingular prime for a given elliptic curve is a prime number with a certain relationship to that curve. If the curve E is defined over the rational numbers, then a prime p is supersingular for E if the reduction of E modulo p ... |
epfl-collab | Tick the \textbf{false} statement regarding the DES round function. | ['There is an expansion operation $E$ from 32 to 48 bits.', 'There is a permutation $P$ on 32-bits.', 'There are $8$ identical S-boxes (substitution boxes) of size $6 \\times 4$.', 'A round key is XORed to an internal register.'] | C | null | Document 1:::
Round constant
. {\displaystyle R_{1},R_{2},...} are implemented using the same function, parameterized by the round constant and, for block ciphers, the round key from the key schedule. Parameterization is essential to reduce the self-similarity of the cipher, which could lead to slide attacks.Increasing... |
epfl-collab | Which of the following ciphers is based on arithmetics over the finite field $\mathrm{GF}(2^8)$? | ['A5/1', 'DES', 'AES', 'RC4'] | C | null | Document 1:::
Finite field arithmetic
In mathematics, finite field arithmetic is arithmetic in a finite field (a field containing a finite number of elements) contrary to arithmetic in a field with an infinite number of elements, like the field of rational numbers. There are infinitely many different finite fields. The... |
epfl-collab | Ensuring the information integrity means that\dots | ['\\dots the information should not leak to any unexpected party.', '\\dots DES is secure.', '\\dots the information should make clear who the author of it is.', '\\dots the information must be protected against any malicious modification.'] | D | null | Document 1:::
Data fidelity
Data integrity is the maintenance of, and the assurance of, data accuracy and consistency over its entire life-cycle and is a critical aspect to the design, implementation, and usage of any system that stores, processes, or retrieves data. The term is broad in scope and may have widely diffe... |
epfl-collab | Given an odd prime $p$, for any $a \in \mathbb{Z}_p$ the equation | ['$x^2 - a = 0$ always has a solution.', '$x^2 - a = 0$ has at most two solutions.', '$x^2 - a = 0$ has exactly two solutions.', '$x^2 - a = 0$ may have four solutions.'] | B | null | Document 1:::
Euler pseudoprime
In arithmetic, an odd composite integer n is called an Euler pseudoprime to base a, if a and n are coprime, and a ( n − 1 ) / 2 ≡ ± 1 ( mod n ) {\displaystyle a^{(n-1)/2}\equiv \pm 1{\pmod {n}}} (where mod refers to the modulo operation). The motivation for this definition is the fact th... |
epfl-collab | Which one of the following notions is not in the fundamental trilogy of cryptography? | ['authentication', 'integrity', 'privacy', 'confidentiality'] | C | null | Document 1:::
Non-commutative cryptography
Non-commutative cryptography is the area of cryptology where the cryptographic primitives, methods and systems are based on algebraic structures like semigroups, groups and rings which are non-commutative. One of the earliest applications of a non-commutative algebraic structu... |
epfl-collab | Consider a mobile station (MS) with a SIM card associated to a home network (HN). The MS tries to connect to a visited network (VN). In the GSM authentication, who knows the key $K_i$? | ['SIM only.', 'SIM and HN.', 'SIM, MS, VN and HN.', 'SIM, MS and HN.'] | B | null | Document 1:::
Cell Global Identity
Cell Global Identity (CGI) is a globally unique identifier for a Base Transceiver Station in mobile phone networks. It consists of four parts: Mobile Country Code (MCC), Mobile Network Code (MNC), Location Area Code (LAC) and Cell Identification (CI). It is an integral part of 3GPP sp... |
epfl-collab | Select \emph{incorrect} statement. Brithday paradox | ['can be implemented using a table of size $\\Theta\\sqrt{N}$', 'is a brute force technique.', 'can be implemented with constant memory using Rho ($\\rho$) method.', 'is used to recover the secret key of AES in $2^{64}$ computations.'] | D | null | Document 1:::
Kleene–Rosser paradox
In mathematics, the Kleene–Rosser paradox is a paradox that shows that certain systems of formal logic are inconsistent, in particular the version of Haskell Curry's combinatory logic introduced in 1930, and Alonzo Church's original lambda calculus, introduced in 1932–1933, both orig... |
epfl-collab | The Kerckhoffs principle says: | ['security should not rely on the secrecy of the cryptosystem itself.', 'the speed of CPUs doubles every 18 months', 'security should not rely on the secrecy of the key.', 'cryptosystems must be published.'] | A | null | Document 1:::
Kerckhoffs's principle
Kerckhoffs's principle (also called Kerckhoffs's desideratum, assumption, axiom, doctrine or law) of cryptography was stated by Dutch-born cryptographer Auguste Kerckhoffs in the 19th century. The principle holds that a cryptosystem should be secure, even if everything about the sys... |
epfl-collab | Tick the \emph{correct} assertion. The Vernam cipher provides \dots | ['integrity.', 'authenticity.', 'none of the mentioned properties.', 'confidentiality.'] | D | null | Document 1:::
CryptMT
In cryptography, CryptMT is a stream cipher algorithm which internally uses the Mersenne twister. It was developed by Makoto Matsumoto, Mariko Hagita, Takuji Nishimura and Mutsuo Saito and is patented. It has been submitted to the eSTREAM project of the eCRYPT network. In that submission to eSTREA... |
epfl-collab | What is the average complexity of exhaustive search when the key is distributed uniformly at random over $N$ keys? | ['$\\frac{N+1}{2}$', '$\\sqrt{N}$', '$\\log N$', '$2^N$'] | A | null | Document 1:::
Search algorithms
Finally, hashing directly maps keys to records based on a hash function.Algorithms are often evaluated by their computational complexity, or maximum theoretical run time. Binary search functions, for example, have a maximum complexity of O(log n), or logarithmic time. In simple terms, th... |
epfl-collab | Select \emph{incorrect} statement. Generic attacks on DES include | ['time memory tradeof against 2 key Triple DES.', 'known plaintext attack by Van Oorschot-Wiener agains 2 key Triple DES.', 'collision attack against 3 key Triple DES.', 'meet in the middle attack against 3 key Triple DES.'] | C | null | Document 1:::
Padding oracle attack
In cryptography, a padding oracle attack is an attack which uses the padding validation of a cryptographic message to decrypt the ciphertext. In cryptography, variable-length plaintext messages often have to be padded (expanded) to be compatible with the underlying cryptographic prim... |
epfl-collab | AES\dots | ['\\dots has a fixed key length \\emph{and} a variable block length.', '\\dots has a variable key length \\emph{and} a fixed block length.', '\\dots has a fixed key length \\emph{and} a fixed block length.', '\\dots has a variable key length \\emph{and} a variable block length.'] | B | null | Document 1:::
Dot-decimal notation
Dot-decimal notation is a presentation format for numerical data. It consists of a string of decimal numbers, using the full stop (dot) as a separation character.A common use of dot-decimal notation is in information technology where it is a method of writing numbers in octet-grouped ... |
epfl-collab | Given that $100000000003$ is prime, what is the cardinality of $\mathbf{Z}_{200000000006}^*$? | ['$100000000002$', '$100000000003$', '$200000000006$', '$2$'] | A | null | Document 1:::
Mersenne numbers
The largest known prime number, 282,589,933 − 1, is a Mersenne prime. Since 1997, all newly found Mersenne primes have been discovered by the Great Internet Mersenne Prime Search, a distributed computing project. In December 2020, a major milestone in the project was passed after all expo... |
epfl-collab | Select the \emph{incorrect} statement. Elliptic Curve Diffie-Hellman is | ['based on the difficulty of computing the discrete logarithm in EC.', 'used for epassports.', 'based on the difficulty of factoring the polynomial of EC.', 'used in Bluetooth 2.1.'] | C | null | Document 1:::
Elliptic-curve Diffie-Hellman
Elliptic-curve Diffie–Hellman (ECDH) is a key agreement protocol that allows two parties, each having an elliptic-curve public–private key pair, to establish a shared secret over an insecure channel. This shared secret may be directly used as a key, or to derive another key. ... |
epfl-collab | In which attack scenario does the adversary ask for the decryption of selected messages? | ['Ciphertext only attack', 'Known plaintext attack', 'Chosen plaintext attack', 'Chosen ciphertext attack'] | D | null | Document 1:::
Padding oracle attack
In cryptography, a padding oracle attack is an attack which uses the padding validation of a cryptographic message to decrypt the ciphertext. In cryptography, variable-length plaintext messages often have to be padded (expanded) to be compatible with the underlying cryptographic prim... |
epfl-collab | An element of the finite field $\mathrm{GF}(2^8)$ is usually represented by\dots | ['\\dots one hexadecimal digit.', '\\dots two hexadecimal digits.', '\\dots an irreducible polynomial of degree 8.', '\\dots eight bytes.'] | B | null | Document 1:::
Binary field
GF(2) (also denoted F 2 {\displaystyle \mathbb {F} _{2}} , Z/2Z or Z / 2 Z {\displaystyle \mathbb {Z} /2\mathbb {Z} } ) is the finite field of two elements (GF is the initialism of Galois field, another name for finite fields). Notations Z2 and Z 2 {\displaystyle \mathbb {Z} _{2}} may be enco... |
epfl-collab | Consider $GF(8)$ defined as $\mathbb{Z}_2[X]/(P(X))$ with $P(x) = X^3 + X + 1$. Compute $X^2 \times (X + 1)$ in $\mathbb{Z}_2[X]/(P(X))$ | ['$X^2+X+1$.', '$X+1$.', '$X^2 + 1$.', '$X^2$.'] | A | null | Document 1:::
Fermat (computer algebra system)
To implement (most) finite fields, the user finds an irreducible monic polynomial in a symbolic variable, say p ( t 1 ) , {\displaystyle p(t_{1}),} and commands Fermat to mod out by it. This may be continued recursively, q ( t 2 , t 1 ) , {\displaystyle q(t_{2},t_{1}),} et... |
epfl-collab | Let $n$ be a positive integer. An element $x \in \mathbb{Z}_n$ is \emph{always} invertible when \dots | ['$x$ is even.', '$x$ and $n$ are coprime.', '$x$ and $\\varphi(n)$ are coprime.', '$n$ is prime.'] | B | null | Document 1:::
Invertible element
For example, consider the functions from the integers to the integers. The doubling function x ↦ 2 x {\displaystyle x\mapsto 2x} has infinitely many left inverses under function composition, which are the functions that divide by two the even numbers, and give any value to odd numbers.
... |
epfl-collab | Which of these attacks applies to the Diffie-Hellman key exchange when the channel cannot be authenticated? | ['Birthday Paradox', 'Attack on low exponents', 'Man-in-the-middle attack', 'Meet-in-the-middle attack'] | C | null | Document 1:::
Elliptic-curve Diffie-Hellman
Elliptic-curve Diffie–Hellman (ECDH) is a key agreement protocol that allows two parties, each having an elliptic-curve public–private key pair, to establish a shared secret over an insecure channel. This shared secret may be directly used as a key, or to derive another key. ... |
epfl-collab | Which of the following is an acceptable commitment scheme, i.e., one that verifies the hiding and binding property (for a well chosen primitive and suitable $x$ and $r$): | ['$Commit(x;r) = H(r\\|x)$, where $H$ is a hash function and $\\|$ denotes the concatenation.', '$Commit(x;r) = Enc_r(x)$, where $Enc_r$ is a symmetric encryption scheme with key $r$.', '$Commit(x;r) = H(x)$, where $H$ is a hash function.', '$Commit(x;r) = x \\oplus r$, where $\\oplus$ is the bitwise xor operation.'] | A | null | Document 1:::
Sub-group hiding
The sub-group hiding assumption is a computational hardness assumption used in elliptic curve cryptography and pairing-based cryptography. It was first introduced in to build a 2-DNF homomorphic encryption scheme.
Document 2:::
Zero-knowledge proofs
A zero-knowledge proof of some statemen... |
epfl-collab | A 128-bit key ... | ['is too long for any practical application.', 'adresses $n^2$ problem for $n=2^{64}$.', 'has 128 decimal digits.', 'provides reasonable security for at least four decades.'] | D | null | Document 1:::
LILI-128
LILI-128 is an LFSR based synchronous stream cipher with a 128-bit key. On 13 November 2000, LILI-128 was presented at the NESSIE workshop. It is designed to be simple to implement in both software and hardware. In 2007, LILI-128 was totally broken by using a notebook running MATLAB in 1.61 hours... |
epfl-collab | Consider a hash function $H$ with $n$ output bits. Tick the \emph{incorrect} assertion. | ['It is possible to find an output collision of $H$ with $O(2^{\\frac{n}{2}})$ memory and $O(1)$ running time.', 'Due to birthday paradox, an output collision of $H$ can be found much faster than with running time $2^n$.', 'It is possible to find an output collision of $H$ with $O(1)$ memory and $O(2^{\\frac{n}{2}})$ r... | A | null | Document 1:::
Minimal perfect hash function
In computer science, a perfect hash function h for a set S is a hash function that maps distinct elements in S to a set of m integers, with no collisions. In mathematical terms, it is an injective function. Perfect hash functions may be used to implement a lookup table with c... |
epfl-collab | Enigma | ['has approximately $2^{256}$ possible keys', 'was a predecessor of a Turing machine model - a basis of Von Neumann architecture', 'achieves perfect security as was required due to military application', 'follows the Kerkhoffs principle'] | D | null | Document 1:::
Crypt (Unix)
In Unix computing, crypt or enigma is a utility program used for encryption. Due to the ease of breaking it, it is considered to be obsolete. The program is usually used as a filter, and it has traditionally been implemented using a "rotor machine" algorithm based on the Enigma machine. It is... |
epfl-collab | Tick the \emph{incorrect} assertion. In RSA with public key $(e,N)$ and private key $(d,N)$ \ldots | ['$e=3$ can be a valid choice of the public key-exponent.', 'we can recover $d$ if we can compute square root modulo $N$ efficiently.', 'we must have that $\\gcd(e,d) = 1$ to be able to decrypt unambiguously.', 'to decrypt a ciphertext $c$, we compute $c^d \\bmod{N}$.'] | C | null | Document 1:::
Decision Linear assumption
The Decision Linear (DLIN) assumption is a computational hardness assumption used in elliptic curve cryptography. In particular, the DLIN assumption is useful in settings where the decisional Diffie–Hellman assumption does not hold (as is often the case in pairing-based cryptogr... |
epfl-collab | Tick the \emph{false} assertion concerning WEP | ['In WEP, encryption is based on a block cipher.', 'WPA-TKIP was designed as a quick fix for WEP.', 'In WEP, encryption is based on RC4.', 'In WEP, IVs repeat themselves too often.'] | A | null | Document 1:::
False (logic)
In logic, false or untrue is the state of possessing negative truth value and is a nullary logical connective. In a truth-functional system of propositional logic, it is one of two postulated truth values, along with its negation, truth. Usual notations of the false are 0 (especially in Bool... |
epfl-collab | Let $n$ be an integer. Which of the following is \emph{not} a group in the general case? | ['$(\\mathbf{Z}_n,+ \\pmod{n})$', '$(\\mathbf{Q}\\setminus \\{0\\},\\times)$', '$(\\mathbf{Z}_n,\\times \\pmod{n})$', '$(\\mathbf{R},+)$'] | C | null | Document 1:::
N-group (finite group theory)
In mathematical finite group theory, an N-group is a group all of whose local subgroups (that is, the normalizers of nontrivial p-subgroups) are solvable groups. The non-solvable ones were classified by Thompson during his work on finding all the minimal finite simple groups.... |
epfl-collab | Tick the \textbf{true} statement. | ['For all $n \\geq 2$ and all $x \\in \\mathbb{Z}_n$, $x$ is invertible if and only if $x$ divides $n$.', 'For all $n \\geq 2$, $\\mathbb{Z}_n^*$ has order of $n-1$.', 'If $x \\in \\mathbb{Z}_n^*$ has an order of $m$, then $x^i \\equiv x^{i \\pmod{m}} \\pmod{n} $ for all $i\\in \\mathbb{Z}$.', 'For all $x \\in \\mathbb... | C | null | Document 1:::
Vector clocks
Each time a process experiences an internal event, it increments its own logical clock in the vector by one. For instance, upon an event at process i {\displaystyle i} , it updates V C i ← V C i + 1 {\displaystyle VC_{i}\leftarrow VC_{i}+1} . Each time a process sends a message, it increme... |
epfl-collab | What is $\varphi(48)$? | ['$16$', '$30$', '$24$', '$47$'] | A | null | Document 1:::
Abell 48
Abell 48 is a planetary nebula likely located around 14,000 light years away in the constellation of Aquila. It is noteworthy among planetary nebulae for hosting a rare WN-type Wolf-Rayet-type central star, a -type star, which was once thought to be a bona-fide Wolf-Rayet star, and received the n... |
epfl-collab | Tick the true assertion. | ['A dictionary attack requires less memory than a time-memory tradeoff.', 'AES is the ancestor of DES.', 'Double-DES succumbs under a Meet-in-the-Middle attack.', 'IDEA has the same round functions as DES.'] | C | null | Document 1:::
Assertion (software development)
In computer programming, specifically when using the imperative programming paradigm, an assertion is a predicate (a Boolean-valued function over the state space, usually expressed as a logical proposition using the variables of a program) connected to a point in the progr... |
epfl-collab | Tick the \emph{correct} assertion. | ['The Keccak hash function is based on the Merkle-Damg{\\aa}rd construction.', 'MD5 is using a compression function based on the Davies-Meyer scheme.', 'Plain CBCMAC is resistant to forgery attacks.', 'GCM is an efficient MAC based on the CBC mode.'] | B | null | Document 1:::
Assertion (software development)
In computer programming, specifically when using the imperative programming paradigm, an assertion is a predicate (a Boolean-valued function over the state space, usually expressed as a logical proposition using the variables of a program) connected to a point in the progr... |
epfl-collab | The Time-Memory Tradeoff Attack ... | ['can be combined with birthday paradox to find the order of the group in RSA efficiently.', 'is useful for finding a preimage within complexity $O\\big(\\big({\\frac{2}{3}}\\big)^N\\big).$', 'is a dedicated method which works only on SHA1.', 'is useful for finding a preimage within complexity $O(N^{\\frac{2}{3}}).$'] | D | null | Document 1:::
Time/memory/data tradeoff attack
A time/memory/data tradeoff attack is a type of cryptographic attack where an attacker tries to achieve a situation similar to the space–time tradeoff but with the additional parameter of data, representing the amount of data available to the attacker. An attacker balances... |
epfl-collab | Let $f: \mathbb{Z}_{m n} \rightarrow \mathbb{Z}_m \times \mathbb{Z}_n$ be defined by $f (x) = (x \bmod m,x \bmod n)$. Then $f$ is a ring isomorphism between $\mathbb{Z}_{180}$ and: | ['$\\mathbb{Z}_{4} \\times \\mathbb{Z}_{45}$.', '$\\mathbb{Z}_{6} \\times \\mathbb{Z}_{30}$.', '$\\mathbb{Z}_{2} \\times \\mathbb{Z}_{90}$.', '$\\mathbb{Z}_{10} \\times \\mathbb{Z}_{18}$.'] | A | null | Document 1:::
First ring isomorphism theorem
In mathematics, specifically abstract algebra, the isomorphism theorems (also known as Noether's isomorphism theorems) are theorems that describe the relationship between quotients, homomorphisms, and subobjects. Versions of the theorems exist for groups, rings, vector space... |
epfl-collab | A Carmichael number $n$ ... | ['is a prime number.', 'will be considered as a prime by the Miller-Rabin algorithm.', "will always pass Fermat's test for any $0 < b < n$.", 'verifies that $\\forall b$, $\\mathsf{gcd}(b,n)=1$ implies that $b^{n-1} \\equiv 1 \\ \\pmod n $.'] | D | null | Document 1:::
Carmichael number
In number theory, a Carmichael number is a composite number n {\displaystyle n} , which in modular arithmetic satisfies the congruence relation: b n ≡ b ( mod n ) {\displaystyle b^{n}\equiv b{\pmod {n}}} for all integers b {\displaystyle b} . The relation may also be expressed in the for... |
epfl-collab | Which symmetric key primitive is used in WPA2 encryption? | ['MD5 OFB Mode', 'RC4 CBC Mode', 'AES CCM Mode', 'KASUMI ECB Mode'] | C | null | Document 1:::
KRACK
The weakness is exhibited in the Wi-Fi standard itself, and not due to errors in the implementation of a sound standard by individual products or implementations. Therefore, any correct implementation of WPA2 is likely to be vulnerable. The vulnerability affects all major software platforms, includi... |
epfl-collab | Let $n$ be an integer. What is the cardinality of $\mathbf{Z}^*_n$? | ['$n$', '$\\varphi(n-1)$', '$n-1$', '$\\varphi(n)$'] | D | null | Document 1:::
Euler's formula
For complex z Here, n is restricted to positive integers, so there is no question about what the power with exponent n means.
Document 2:::
Finite index
More generally, | Z: n Z | = n {\displaystyle |\mathbb {Z} :n\mathbb {Z} |=n} for any positive integer n. When G is finite, the formula m... |
epfl-collab | Let $n$ be any positive integer. Three of the following assertions are equivalent. Tick the remaining one. | ['$\\mathbb{Z}_n$ is a field.', '$n$ is a prime power.', 'Any element $x \\in \\mathbb{Z}_n \\backslash \\{0\\}$ is invertible.', '$\\varphi(n)=n-1 $, where $\\varphi$ denotes the Euler totient function.'] | B | null | Document 1:::
Idoneal number
A positive integer n is idoneal if and only if it cannot be written as ab + bc + ac for distinct positive integers a, b, and c.It is sufficient to consider the set { n + k2 | 3 . k2 ≤ n ∧ gcd (n, k) = 1 }; if all these numbers are of the form p, p2, 2 · p or 2s for some integer s, where p i... |
epfl-collab | Birthday attacks \dots | ['are equivalent to exhaustive search.', 'imply that a majority of people is born in Spring.', 'are used to break Google Calendars.', 'can be used to find collisions in hash functions.'] | D | null | Document 1:::
Dot plot (statistics)
A dot chart or dot plot is a statistical chart consisting of data points plotted on a fairly simple scale, typically using filled in circles. There are two common, yet very different, versions of the dot chart. The first has been used in hand-drawn (pre-computer era) graphs to depict... |
epfl-collab | What is the number of secret bits in a WEP key? | ['64 or 128 bytes.', '40 or 104 bytes.', '40 or 104 bits.', '64 or 128 bits.'] | C | null | Document 1:::
40-bit encryption
40-bit encryption refers to a (now broken) key size of forty bits, or five bytes, for symmetric encryption; this represents a relatively low level of security. A forty bit length corresponds to a total of 240 possible keys. Although this is a large number in human terms (about a trillion... |
epfl-collab | Tick the \emph{incorrect} assertion. In a multiplicative cyclic group $G$ of order $m > 1$ with neutral element $e_G$ \ldots | ['the order of every element $x \\in G$ is $m$.', 'there exists $g \\in G$ that generates the whole group.', '$\\lambda = m$, where $\\lambda$ is the exponent of $G$.', 'for any $x \\in G$, we have that $x^m = e_{G}$.'] | A | null | Document 1:::
Finite cyclic group
For any element g in any group G, one can form the subgroup that consists of all its integer powers: ⟨g⟩ = { gk | k ∈ Z }, called the cyclic subgroup generated by g. The order of g is |⟨g⟩|, the number of elements in ⟨g⟩, conventionally abbreviated as |g|, as ord(g), or as o(g). That i... |
epfl-collab | Which one of the following notions means that ``the information must be protected against any malicious modification''? | ['confidentiality.', 'integrity.', 'reliability.', 'privacy.'] | B | null | Document 1:::
Clark–Wilson model
The Clark–Wilson integrity model provides a foundation for specifying and analyzing an integrity policy for a computing system. The model is primarily concerned with formalizing the notion of information integrity. Information integrity is maintained by preventing corruption of data ite... |
epfl-collab | Confidentiality means that: | ['the message can be read by anyone.', 'the information must be protected against any malicious modification.', 'the message should make clear who the author is.', 'information should not leak to any unexpected party.'] | D | null | Document 1:::
Electronic health record confidentiality
Electronic health record medical healthcare systems are developing widely. Things are being moved from the manual ways to automation and the patient records and health records are also being recorded electronically. One important aspect of any health record system ... |
epfl-collab | Which of the following acronyms does not designate a mode of operation? | ['ECB', 'CRC', 'CTR', 'CBC'] | B | null | Document 1:::
Security Modes
Generally, security modes refer to information systems security modes of operations used in mandatory access control (MAC) systems. Often, these systems contain information at various levels of security classification. The mode of operation is determined by: The type of users who will be di... |
epfl-collab | Select the \emph{incorrect} statement. The brute force attack \dots | ['can break a cipher with a $128$-bit key on your PC today.', 'has higher worst case complexity than average case complexity.', 'refers to a way of getting the secret key, exhaustively.', "can be applicable after decades according to Moore's law."] | A | null | Document 1:::
Brute force attack
In cryptography, a brute-force attack consists of an attacker submitting many passwords or passphrases with the hope of eventually guessing correctly. The attacker systematically checks all possible passwords and passphrases until the correct one is found. Alternatively, the attacker ca... |
epfl-collab | WEP \dots | ['is badly broken.', 'provides good confidentiality.', 'provides good authentication.', 'provides good message integrity.'] | A | null | Document 1:::
Dot-decimal notation
Dot-decimal notation is a presentation format for numerical data. It consists of a string of decimal numbers, using the full stop (dot) as a separation character.A common use of dot-decimal notation is in information technology where it is a method of writing numbers in octet-grouped ... |
epfl-collab | The DES key schedule\dots | ['\\dots in only used during the encryption phase, not during the decryption phase.', '\\dots generates 16 subkeys.', '\\dots takes as an input a key of 128 bits.', '\\dots is based on a Feistel scheme.'] | B | null | Document 1:::
Key Sequenced Data Set
A key-sequenced data set (KSDS) is a type of data set used by IBM's VSAM computer data storage system. : 5 Each record in a KSDS data file is embedded with a unique key. : 20 A KSDS consists of two parts, the data component and a separate index file known as the index component whic... |
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