question stringlengths 6 313 | choices listlengths 4 4 | answer stringclasses 4
values | source stringclasses 1
value | __index_level_0__ int64 1 337 |
|---|---|---|---|---|
In which of the following groups is the decisional Diffie-Hellman problem (DDH) believed to be hard? | [
"In $\\mathbb{Z}_p$, with a large prime $p$.",
"In large subgroup of smooth order of a ``regular'' elliptic curve.",
"In a large subgroup of prime order of $\\mathbb{Z}_p^*$, such that $p$ is a large prime.",
"In $\\mathbb{Z}_p^*$, with a large prime $p$."
] | C | m1_pref_dataset | 301 |
In ElGamal signature scheme and over the random choice of the public parameters in the random oracle model (provided that the DLP is hard), existential forgery is \ldots | [
"\\ldots impossible.",
"\\ldots hard on average.",
"\\ldots easy on average.",
"\\ldots easy."
] | B | m1_pref_dataset | 302 |
Which of the following primitives \textit{cannot} be instantiated with a cryptographic hash function? | [
"A pseudo-random number generator.",
"A commitment scheme.",
"A public key encryption scheme.",
"A key-derivation function."
] | C | m1_pref_dataset | 303 |
In plain ElGamal Encryption scheme \ldots | [
"\\ldots only a confidential channel is needed.",
"\\ldots only an authenticated channel is needed.",
"\\ldots only an integer channel is needed",
"\\ldots only an authenticated and integer channel is needed."
] | D | m1_pref_dataset | 304 |
Tick the \textbf{true} assertion. Let $X$ be a random variable defined by the visible face showing up when throwing a dice. Its expected value $E(X)$ is: | [
"3.5",
"3",
"1",
"4"
] | A | m1_pref_dataset | 305 |
Consider an arbitrary cipher $C$ and a uniformly distributed random permutation $C^*$ on $\{0,1\}^n$. Tick the \textbf{false} assertion. | [
"$\\mathsf{Dec}^1(C)=0$ implies $C=C^*$.",
"$\\mathsf{Dec}^1(C)=0$ implies $[C]^1=[C^*]^1$.",
"$\\mathsf{Dec}^1(C)=0$ implies that $C$ is perfectly decorrelated at order 1.",
"$\\mathsf{Dec}^1(C)=0$ implies that all coefficients in $[C]^1$ are equal to $\\frac{1}{2^n}$."
] | A | m1_pref_dataset | 306 |
Tick the \textit{incorrect} assertion. Let $P, V$ be an interactive system for a language $L\in \mathcal{NP}$. | [
"The proof system is $\\beta$-sound if $\\Pr[\\text{Out}_{V}(P^* \\xleftrightarrow{x} V) = \\text{accept}] \\leq \\beta$ for any $P^*$ and any $x \\notin L$.",
"The soundness of the proof system can always be tuned close to $0$ by sequential composition.",
"It is impossible for the proof system to be sound and ... | C | m1_pref_dataset | 307 |
Tick the assertion related to an open problem. | [
"$NP\\subseteq IP$.",
"$P\\subseteq IP$.",
"$PSPACE=IP$.",
"$NP = \\text{co-}NP$."
] | D | m1_pref_dataset | 308 |
Let $X$ be a plaintext and $Y$ its ciphertext. Which statement is \textbf{not} equivalent to the others? | [
"the encyption scheme provides perfect secrecy",
"only a quantum computer can retrieve $X$ given $Y$",
"$X$ and $Y$ are statistically independent random variables",
"the conditionnal entropy of $X$ given $Y$ is equal to the entropy of $X$"
] | B | m1_pref_dataset | 309 |
Tick the \textbf{\emph{incorrect}} assertion. A $\Sigma$-protocol \dots | [
"has special soundness.",
"is zero-knowledge.",
"is a 3-move interaction.",
"has the verifier polynomially bounded."
] | B | m1_pref_dataset | 310 |
The statistical distance between two distributions is \dots | [
"unrelated to the advantage of a distinguisher.",
"a lower bound on the advantage of \\emph{all} distinguishers (with a unique sample).",
"an upper bound on the advantage of \\emph{all} distinguishers (with a unique sample).",
"an upper bound on the advantage of all distinguishers making statistics on the obt... | C | m1_pref_dataset | 311 |
Tick the \textbf{\emph{correct}} assertion. A random oracle $\ldots$ | [
"returns the same answer when queried with two different values.",
"is instantiated with a hash function in practice.",
"has predictable output before any query is made.",
"answers with random values that are always independent of the previous queries."
] | B | m1_pref_dataset | 312 |
Consider an Sbox $S:\{0,1\}^m \rightarrow \{0,1\}^m$. We have that \ldots | [
"$\\mathsf{DP}^S(0,b)=1$ if and only if $S$ is a permutation.",
"$\\sum_{b\\in \\{0,1\\}^m} \\mathsf{DP}^S(a,b)$ is even.",
"$\\sum_{b\\in \\{0,1\\}^m \\backslash \\{0\\}} \\mathsf{DP}^S(0,b)= 0$",
"$\\mathsf{DP}^S(0,b)=1$ if and only if $m$ is odd."
] | C | m1_pref_dataset | 313 |
Tick the \textbf{true} assertion. In RSA \ldots | [
"\\ldots decryption is known to be equivalent to factoring.",
"\\ldots key recovery is provably not equivalent to factoring).",
"\\ldots decryption is probabilistic.",
"\\ldots public key transmission needs authenticated and integer channel."
] | D | m1_pref_dataset | 314 |
Consider the cipher defined by $$\begin{array}{llll} C : & \{0,1\}^{4} & \rightarrow & \{0,1\}^{4} \\ & x & \mapsto & C(x)=x \oplus 0110 \\ \end{array} $$ The value $LP^C(1,1)$ is equal to | [
"$0$",
"$1/4$",
"$1/2$",
"$1$"
] | D | m1_pref_dataset | 315 |
Let $n=pq$ be a RSA modulus and let $(e,d)$ be a RSA public/private key. Tick the \emph{correct} assertion. | [
"Finding a multiple of $\\lambda(n)$ is equivalent to decrypt a ciphertext.",
"$ed$ is a multiple of $\\phi(n)$.",
"The two roots of the equation $X^2 - (n-\\phi(n)+1)X+n$ in $\\mathbb{Z}$ are $p$ and $q$.",
"$e$ is the inverse of $d$ mod $n$."
] | C | m1_pref_dataset | 316 |
Tick the \emph{true} assertion. A distinguishing attack against a block cipher\dots | [
"is a probabilistic attack.",
"succeeds with probability $1$.",
"outputs the secret key.",
"succeeds with probability $0$."
] | A | m1_pref_dataset | 317 |
Tick the \textbf{true} assertion. Let $n >1 $ be a composite integer, the product of two primes. Then, | [
"$\\phi(n)$ divides $\\lambda(n)$.",
"$\\lambda(n)$ divides the order of any element $a$ in $\\mathbb{Z}_n$.",
"$\\mathbb{Z}^{*}_n$ with the multiplication is a cyclic group.",
"$a^{\\lambda(n)} \\mod n=1$, for all $a \\in \\mathbb{Z}^{*}_n$."
] | D | m1_pref_dataset | 318 |
Let $C$ be a permutation over $\left\{ 0,1 \right\}^p$. Tick the \emph{incorrect} assertion: | [
"$\\text{DP}^C(a,0) = 1$ for some $a \\neq 0$.",
"$\\text{DP}^C(0,b) = 0$ for some $b \\neq 0$.",
"$\\sum_{b \\in \\left\\{ 0,1 \\right\\}^p}\\text{DP}^C(a,b) = 1$ for any $a\\in \\left\\{ 0,1 \\right\\}^p$.",
"$2^p \\text{DP}^C(a,b) \\bmod 2 = 0$, for any $a,b\\in \\left\\{ 0,1 \\right\\}^p$."
] | A | m1_pref_dataset | 319 |
Tick the \textbf{true} assertion. Assume an arbitrary $f:\{0,1\}^p \rightarrow \{0,1\}^q$, where $p$ and $q$ are integers. | [
"$\\mathsf{DP}^f(a,b)=\\displaystyle\\Pr_{X\\in_U\\{0,1\\}^p}[f(X\\oplus a)\\oplus f(X)\\oplus b=1]$, for all $a \\in \\{0,1\\}^p$, $b \\in \\{0,1\\}^q$.",
"$\\Pr[f(x\\oplus a)\\oplus f(x)\\oplus b=0]=E(\\mathsf{DP}^f(a,b))$, for all $a, x \\in \\{0,1\\}^p$, $b \\in \\{0,1\\}^q$.",
"$2^p\\mathsf{DP}^f(a,b)$ is ... | D | m1_pref_dataset | 320 |
Tick the \textbf{false} assertion. In order to have zero-knowledge from $\Sigma$-protocols, we need to add the use of \ldots | [
"\\ldots an ephemeral key $h$ and a Pedersen commitment.",
"\\ldots a common reference string.",
"\\ldots hash functions.",
"\\ldots none of the above is necessary, zero-knowledge is already contained in $\\Sigma$-protocols."
] | D | m1_pref_dataset | 321 |
A Feistel scheme is used in\dots | [
"DES",
"AES",
"FOX",
"CS-Cipher"
] | A | m1_pref_dataset | 322 |
Tick the \textbf{false} assertion. The SEI of the distribution $P$ of support $G$ \ldots | [
"is equal to \\# $G\\cdot\\displaystyle\\sum_{x\\in G}\\left(P(x)-\\frac{1}{\\sharp G}\\right)^2$",
"is the advantage of the best distinguisher between $P$ and the uniform distribution.",
"denotes the Squared Euclidean Imbalance.",
"is positive."
] | B | m1_pref_dataset | 323 |
Let $X$, $Y$, and $K$ be respectively the plaintext, ciphertext, and key distributions. $H$ denotes the Shannon entropy. Considering that the cipher achieves \emph{perfect secrecy}, tick the \textbf{false} assertion: | [
"$X$ and $Y$ are statistically independent",
"$H(X,Y)=H(X)$",
"VAUDENAY can be the result of the encryption of ALPACINO using the Vernam cipher.",
"$H(X|Y)=H(X)$"
] | B | m1_pref_dataset | 324 |
Tick the \emph{correct} assertion. Assume that $C$ is an arbitrary random permutation. | [
"$\\mathsf{BestAdv}_n(C,C^\\ast)=\\mathsf{Dec}^n_{\\left|\\left|\\left|\\cdot\\right|\\right|\\right|_\\infty}(C)$",
"$\\mathsf{BestAdv}_n(C,C^\\ast)=\\mathsf{Dec}^{n/2}_{\\left|\\left|\\left|\\cdot\\right|\\right|\\right|_\\infty}(C)$",
"$E(\\mathsf{DP}^{C}(a,b)) < \\frac{1}{2}$",
"$\\mathsf{BestAdv}_n(C,C^\... | D | m1_pref_dataset | 325 |
Which class of languages includes some which cannot be proven by a polynomial-size non-interactive proof? | [
"$\\mathcal{P}$",
"$\\mathcal{IP}$",
"$\\mathcal{NP}$",
"$\\mathcal{NP}\\ \\bigcap\\ $co-$\\mathcal{NP}$"
] | B | m1_pref_dataset | 326 |
Graph coloring consist of coloring all vertices \ldots | [
"\\ldots with a unique color.",
"\\ldots with a different color when they are linked with an edge.",
"\\ldots with a random color.",
"\\ldots with a maximum number of colors."
] | B | m1_pref_dataset | 327 |
What adversarial model does not make sense for a message authentication code (MAC)? | [
"key recovery.",
"universal forgery.",
"existential forgery.",
"decryption."
] | D | m1_pref_dataset | 328 |
Which one of these ciphers does achieve perfect secrecy? | [
"RSA",
"Vernam",
"DES",
"FOX"
] | B | m1_pref_dataset | 329 |
Which of the following problems has not been shown equivalent to the others? | [
"The RSA Key Recovery Problem.",
"The RSA Decryption Problem.",
"The RSA Factorization Problem.",
"The RSA Order Problem."
] | B | m1_pref_dataset | 330 |
A proof system is perfect-black-box zero-knowledge if \dots | [
"for any PPT verifier $V$, there exists a PPT simulator $S$, such that $S$ produces an output which is hard to distinguish from the view of the verifier.",
"for any PPT simulator $S$ and for any PPT verifier $V$, $S^{V}$ produces an output which has the same distribution as the view of the verifier.",
"there ex... | C | m1_pref_dataset | 331 |
Suppose that you can prove the security of your symmetric encryption scheme against the following attacks. In which case is your scheme going to be the \textbf{most} secure? | [
"Key recovery under known plaintext attack.",
"Key recovery under chosen ciphertext attack.",
"Decryption under known plaintext attack.",
"Decryption under chosen ciphertext attack."
] | D | m1_pref_dataset | 332 |
For a $n$-bit block cipher with $k$-bit key, given a plaintext-ciphertext pair, a key exhaustive search has an average number of trials of \dots | [
"$2^n$",
"$2^k$",
"$\\frac{2^n+1}{2}$",
"$\\frac{2^k+1}{2}$"
] | D | m1_pref_dataset | 333 |
Tick the \textbf{false} assertion. For a Vernam cipher... | [
"SUPERMAN can be the result of the encryption of the plaintext ENCRYPT",
"CRYPTO can be used as a key to encrypt the plaintext PLAIN",
"SERGE can be the ciphertext corresponding to the plaintext VAUDENAY",
"The key IAMAKEY can be used to encrypt any message of size up to 7 characters"
] | C | m1_pref_dataset | 334 |
Assume we are in a group $G$ of order $n = p_1^{\alpha_1} p_2^{\alpha_2}$, where $p_1$ and $p_2$ are two distinct primes and $\alpha_1, \alpha_2 \in \mathbb{N}$. The complexity of applying the Pohlig-Hellman algorithm for computing the discrete logarithm in $G$ is \ldots (\emph{choose the most accurate answer}): | [
"$\\mathcal{O}(\\alpha_1 p_1^{\\alpha_1 -1} + \\alpha_2 p_2^{\\alpha_2 -1})$.",
"$\\mathcal{O}(\\sqrt{p_1}^{\\alpha_1} + \\sqrt{p_2}^{\\alpha_2})$.",
"$\\mathcal{O}( \\alpha_1 \\sqrt{p_1} + \\alpha_2 \\sqrt{p_2})$.",
"$\\mathcal{O}( \\alpha_1 \\log{p_1} + \\alpha_2 \\log{p_2})$."
] | C | m1_pref_dataset | 335 |
Tick the \textbf{\emph{incorrect}} assertion. | [
"$P\\subseteq NP$.",
"$NP\\subseteq IP$.",
"$PSPACE\\subseteq IP$.",
"$NP\\mbox{-hard} \\subset P$."
] | D | m1_pref_dataset | 336 |
Tick the \emph{correct} statement. $\Sigma$-protocols \ldots | [
"are defined for any language in \\textrm{PSPACE}.",
"have a polynomially unbounded extractor that can yield a witness.",
"respect the property of zero-knowledge for any verifier.",
"consist of protocols between a prover and a verifier, where the verifier is polynomially bounded."
] | D | m1_pref_dataset | 337 |
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