{"pinia":{"ui":{"prefs":{"theme":"system","textScale":"md","fontFamily":"sans","reducedMotion":false,"highContrast":false}},"academy":{"universities":[],"universitySummaries":[{"slug":"rtu","name":"RTU","fullName":"Rajasthan Technical University","branches":[{"slug":"first-year-common","name":"First Year (Common)"},{"slug":"computer-science","name":"Computer Science"},{"slug":"mechanical","name":"Mechanical"},{"slug":"civil","name":"Civil"},{"slug":"ai-data-science","name":"AI & Data Science"},{"slug":"ee-ec-eee","name":"EE / EC / EEE"}]},{"slug":"aktu","name":"AKTU","fullName":"Dr. A. P. J. Abdul Kalam Technical University","branches":[{"slug":"first-year-common","name":"First Year (Common)"},{"slug":"computer-science","name":"Computer Science"}]}],"activePapers":[{"id":"information-system-security-2021","title":"Information System Security (2021)","subjectSlug":"information-system-security","subjectName":"Information System Security","universitySlug":"rtu","branchSlug":"computer-science","year":4,"semester":7,"examYear":2021,"paperCode":"7E7032","questions":[{"id":"v2-information-system-security-2021-pA-q1","number":1,"marks":2,"tags":["Part A"],"text":[{"type":"paragraph","content":"Define confidentiality, integrity, and availability (CIA Triad)."}],"answer":{"summary":"The CIA Triad mathematically defines absolute information security: Confidentiality (data secrecy), Integrity (data immutability), and Availability (system uptime guarantees).","explanation":[{"type":"paragraph","content":"The CIA Triad is the absolute foundational architecture of cybersecurity. Confidentiality guarantees data is mathematically encrypted (AES) to prevent unauthorized reading. Integrity guarantees via cryptographic hashing (SHA-256) that data is not violently altered. Availability guarantees authorized users have absolute access to the physical servers, defeating DDoS attacks."}]}},{"id":"v2-information-system-security-2021-pA-q2","number":2,"marks":2,"tags":["Part A"],"text":[{"type":"paragraph","content":"What is a cryptographic hash function?"}],"answer":{"summary":"A cryptographic hash function is an irreversible mathematical algorithm that violently compresses arbitrary-length data into a rigidly fixed-size deterministic string (the digest).","explanation":[{"type":"paragraph","content":"A hash function (like SHA-256) mathematically processes a 10-Gigabyte video file and outputs exactly 256 bits. It is a one-way mathematical trapdoor; you cannot decrypt a hash. Its absolute purpose is guaranteeing data integrity—changing a single pixel in the video will completely and violently change the resulting 256-bit hash."}]}},{"id":"v2-information-system-security-2021-pA-q3","number":3,"marks":2,"tags":["Part A"],"text":[{"type":"paragraph","content":"Differentiate between passive and active attacks."}],"answer":{"summary":"Passive attacks silently intercept and read data without altering it, whereas active attacks violently modify the data stream or the physical network architecture.","explanation":[{"type":"paragraph","content":"A Passive Attack (like Packet Sniffing/Eavesdropping) is mathematically invisible to the victim because the raw data is never altered, making detection nearly impossible. An Active Attack (like a Man-in-the-Middle or SYN Flood) aggressively injects malicious packets, violently altering the communication stream and actively damaging system availability."}]}},{"id":"v2-information-system-security-2021-pA-q4","number":4,"marks":2,"tags":["Part A"],"text":[{"type":"paragraph","content":"Define non-repudiation."}],"answer":{"summary":"Non-repudiation is the absolute cryptographic guarantee that a sender cannot mathematically or legally deny having sent a specific digital message.","explanation":[{"type":"paragraph","content":"Non-repudiation is achieved strictly through Asymmetric Public Key Cryptography and Digital Signatures. Because a digital signature is mathematically generated using the sender's absolute, secret Private Key, it provides undeniable, court-admissible proof that the specific sender—and absolutely no one else—authorized the transaction."}]}},{"id":"v2-information-system-security-2021-pA-q5","number":5,"marks":2,"tags":["Part A"],"text":[{"type":"paragraph","content":"What is the avalanche effect in cryptography?"}],"answer":{"summary":"The avalanche effect is a strict cryptographic property where mathematically flipping one single bit in the plaintext causes an explosive, chaotic alteration of the entire ciphertext.","explanation":[{"type":"paragraph","content":"In strong block ciphers like AES, the Avalanche Effect is an absolute requirement to defeat statistical cryptanalysis. If you mathematically change exactly ONE bit of the input key or plaintext, roughly 50% of the bits in the output ciphertext must violently and unpredictably flip. If this fails, the algorithm is broken."}]}},{"id":"v2-information-system-security-2021-pA-q6","number":6,"marks":2,"tags":["Part A"],"text":[{"type":"paragraph","content":"Define a digital signature."}],"answer":{"summary":"A digital signature is a mathematical algorithm utilizing asymmetric cryptography to guarantee the absolute authenticity, integrity, and non-repudiation of a digital document.","explanation":[{"type":"paragraph","content":"A Digital Signature does not encrypt the document. The sender mathematically hashes the document and violently encrypts that Hash with their Private Key. The receiver decrypts it using the sender's Public Key. If the hashes match, it mathematically proves the document was not altered and was sent by the true owner."}]}},{"id":"v2-information-system-security-2021-pA-q7","number":7,"marks":2,"tags":["Part A"],"text":[{"type":"paragraph","content":"What is a Trojan Horse?"}],"answer":{"summary":"A Trojan Horse is malicious software architecture heavily disguised as a legitimate, benign application to mathematically trick users into executing a catastrophic payload.","explanation":[{"type":"paragraph","content":"Unlike a virus, a Trojan does NOT mathematically self-replicate. It relies strictly on psychological social engineering. A user downloads what appears to be a free video game, but upon execution, the Trojan violently opens a hidden backdoor port (e.g., port 4444) granting a hacker absolute remote root access."}]}},{"id":"v2-information-system-security-2021-pA-q8","number":8,"marks":2,"tags":["Part A"],"text":[{"type":"paragraph","content":"Explain the concept of a botnet."}],"answer":{"summary":"A botnet is a massive, highly synchronized architectural network of infected, compromised computers (zombies) controlled entirely by a single hacker's Command and Control (C&C) server.","explanation":[{"type":"paragraph","content":"A Botnet is a catastrophic weapon of mass network destruction. The hacker infects 100,000 IoT devices with malware. These devices silently connect to the C&C server. The hacker can mathematically command all 100,000 nodes to simultaneously blast a target server, executing a horrific Distributed Denial of Service (DDoS) attack."}]}},{"id":"v2-information-system-security-2021-pA-q9","number":9,"marks":2,"tags":["Part A"],"text":[{"type":"paragraph","content":"What is a Denial of Service (DoS) attack?"}],"answer":{"summary":"A DoS attack is an aggressive, mathematically asymmetric network assault designed to violently overwhelm a server's physical RAM or CPU, crashing the system.","explanation":[{"type":"paragraph","content":"A Denial of Service (DoS) attack violates the Availability pillar of the CIA Triad. A single attacker continuously fires malformed packets (like a TCP SYN Flood) at the target. The target server allocates RAM for each fake connection until it mathematically exhausts all physical memory and violently drops legitimate users."}]}},{"id":"v2-information-system-security-2021-pA-q10","number":10,"marks":2,"tags":["Part A"],"text":[{"type":"paragraph","content":"Define Phishing."}],"answer":{"summary":"Phishing is a highly destructive psychological attack where a hacker impersonates a legitimate architecture (like a bank) to steal absolute security credentials.","explanation":[{"type":"paragraph","content":"Phishing entirely bypasses cryptographic mathematics by attacking the human flaw. The attacker sends a perfectly forged email claiming the victim's bank account is locked. The victim clicks the link and enters their password into a mathematically identical, fake server hosted by the hacker, instantly surrendering their credentials."}]}},{"id":"v2-information-system-security-2021-pB-q1","number":11,"marks":4,"tags":["Part B"],"text":[{"type":"paragraph","content":"Explain the working principle of the RSA algorithm with an example."}],"answer":{"summary":"A definitive mathematical exposition on the RSA algorithm. Violently details the prime generation, Euler's Totient, and the exact modular exponentiation required to execute public-key encryption and decryption.","explanation":[{"type":"heading","content":"The Working Principle of the RSA Algorithm"},{"type":"paragraph","content":"Invented by Rivest, Shamir, and Adleman, RSA is the absolute foundation of Asymmetric Cryptography. It completely eradicates the key-distribution problem of symmetric ciphers. Its security is mathematically anchored in the horrific computational difficulty of Integer Factorization."},{"type":"heading","content":"The Mathematical Key Generation"},{"type":"list","items":["**Step 1:** Violently generate two massive, distinct prime numbers, $p$ and $q$. (Example: $p=3, q=11$).","**Step 2:** Mathematically calculate the Modulus $n = p \\times q$. ($n = 33$). This $n$ will be released to the public.","**Step 3:** Calculate Euler's Totient $\\phi(n) = (p-1) \\times (q-1)$. ($\\phi(33) = 2 \\times 10 = 20$).","**Step 4:** Select the Public Exponent $e$. It must be $1 < e < \\phi(n)$, and strictly coprime to $\\phi(n)$. (Let $e=7$).","**Step 5:** Calculate the highly secret Private Exponent $d$. It is the modular multiplicative inverse of $e \\pmod{\\phi(n)}$. Meaning, $(d \\times e) \\equiv 1 \\pmod{\\phi(n)}$. (Let $d=3$, because $3 \\times 7 = 21 \\equiv 1 \\pmod{20}$)."]},{"type":"paragraph","content":"The Public Key is $(e, n) \\rightarrow (7, 33)$. The Private Key is $(d, n) \\rightarrow (3, 33)$."},{"type":"heading","content":"The Mathematical Execution"},{"type":"subheading","content":"Encryption (Sender using Public Key)"},{"type":"paragraph","content":"Let Plaintext Message $M = 2$. The absolute encryption formula is $C = M^e \\pmod{n}$."},{"type":"paragraph","content":"$C = 2^7 \\pmod{33} = 128 \\pmod{33} = 29$. The Ciphertext $C$ is $29$."},{"type":"subheading","content":"Decryption (Receiver using Private Key)"},{"type":"paragraph","content":"The receiver violently unlocks $C$ using their Private Key $d$. Formula: $M = C^d \\pmod{n}$."},{"type":"paragraph","content":"$M = 29^3 \\pmod{33} = 24389 \\pmod{33} = 2$. The absolute original plaintext $2$ is flawlessly recovered."},{"type":"paragraph","content":"A hacker intercepting $C=29$ and $n=33$ cannot find $d$ without knowing $\\phi(n)$, which requires mathematically factoring $n$ back into $p$ and $q$. For massive 2048-bit numbers, this is physically impossible."}]}},{"id":"v2-information-system-security-2021-pB-q2","number":12,"marks":4,"tags":["Part B"],"text":[{"type":"paragraph","content":"Describe the Diffie-Hellman key exchange algorithm."}],"answer":{"summary":"A critical mathematical breakdown of the Diffie-Hellman Key Exchange. Details how two parties can mathematically generate an absolute shared secret over a fully compromised, public channel using Discrete Logarithms.","explanation":[{"type":"heading","content":"The Diffie-Hellman Key Exchange Algorithm"},{"type":"paragraph","content":"Diffie-Hellman (DH) is NOT an encryption algorithm. It is a brilliant mathematical architecture that allows two parties (Alice and Bob) to violently generate an identical, highly secure shared symmetric key while communicating over a completely public, hacker-infested internet. Its absolute security relies on the catastrophic computational difficulty of solving the Discrete Logarithm Problem."},{"type":"heading","content":"The Mathematical Execution"},{"type":"paragraph","content":"Alice and Bob publicly agree on two mathematical constants: a massive prime number $p$, and a base generator $g$. These are sent in absolute plaintext; hackers can see them."},{"type":"list","items":["**Step 1 (Private Secrets):** \n - Alice violently generates a secret integer $a$. She keeps this absolutely hidden.\n - Bob violently generates a secret integer $b$. He keeps this absolutely hidden.","**Step 2 (Public Calculation):** \n - Alice mathematically calculates her Public component: $A = g^a \\pmod{p}$. She sends $A$ to Bob over the public internet.\n - Bob mathematically calculates his Public component: $B = g^b \\pmod{p}$. He sends $B$ to Alice.","**Step 3 (The Genius Shared Secret):** \n - Alice receives $B$. She mathematically calculates the Shared Secret $S = B^a \\pmod{p}$.\n - Bob receives $A$. He mathematically calculates the Shared Secret $S = A^b \\pmod{p}$."]},{"type":"heading","content":"The Mathematical Proof"},{"type":"paragraph","content":"Both Alice and Bob arrive at the EXACT same mathematical number because: \n$B^a = (g^b)^a = g^{ab} \\pmod{p}$ \n$A^b = (g^a)^b = g^{ab} \\pmod{p}$"},{"type":"paragraph","content":"A hacker sniffing the network sees $p, g, A,$ and $B$. To find the secret key $S$, the hacker MUST find Alice's secret $a$ or Bob's secret $b$. To find $a$, the hacker must mathematically solve $A = g^a \\pmod{p}$. This is the Discrete Logarithm Problem, and for a 2048-bit prime $p$, it is mathematically impossible to solve before the universe ends."}]}},{"id":"v2-information-system-security-2021-pB-q3","number":13,"marks":4,"tags":["Part B"],"text":[{"type":"paragraph","content":"What are the differences between symmetric and asymmetric key cryptography?"}],"answer":{"summary":"A definitive architectural comparison between Symmetric and Asymmetric Cryptography. Violently contrasts the explosive processing speed of single-key systems against the massive key-distribution superiority of public/private key pairs.","explanation":[{"type":"heading","content":"Symmetric vs. Asymmetric Cryptography"},{"type":"paragraph","content":"The entire field of cryptographic architecture is mathematically divided into two absolute paradigms based strictly on how cryptographic keys are managed and applied to plaintext."},{"type":"heading","content":"1. Symmetric Key Cryptography"},{"type":"paragraph","content":"Also known as Secret-Key Cryptography (e.g., AES, DES)."},{"type":"list","items":["**Mechanism:** It utilizes exactly ONE absolute mathematical key to both violently encrypt the plaintext and decrypt the ciphertext.","**Merit (Speed):** The mathematical operations (like XOR and bit-shifting) are incredibly simple. It is explosively fast, capable of encrypting 10 Gigabytes of video data in seconds.","**Demerit (Key Distribution):** A catastrophic architectural flaw. If Alice wants to talk to Bob, she must physically or securely hand Bob the single secret key. If a hacker intercepts the key during transit, the entire system is destroyed. Furthermore, a network of 1000 users requires 499,500 unique keys to communicate securely."]},{"type":"heading","content":"2. Asymmetric Key Cryptography"},{"type":"paragraph","content":"Also known as Public-Key Cryptography (e.g., RSA, Elliptic Curve)."},{"type":"list","items":["**Mechanism:** It utilizes a mathematically linked PAIR of keys. A Public Key (shared with the entire world) used exclusively to Encrypt. A highly guarded Private Key used exclusively to Decrypt.","**Merit (Key Distribution):** It completely annihilates the key-distribution crisis. Alice simply broadcasts her Public Key on the internet. Anyone can encrypt a message to her, but ONLY Alice can mathematically decrypt it.","**Demerit (Speed):** The mathematics involve massive prime number modular exponentiation. It is catastrophically slow—up to 1,000 times slower than AES. Therefore, it is never used to encrypt massive files; it is only used to encrypt small symmetric session keys."]}]}},{"id":"v2-information-system-security-2021-pB-q4","number":14,"marks":4,"tags":["Part B"],"text":[{"type":"paragraph","content":"Explain the various modes of operation in block ciphers."}],"answer":{"summary":"A comprehensive theoretical breakdown of Block Cipher Modes of Operation. Details how ECB fails catastrophically at hiding data patterns, while CBC and CTR use mathematical XOR chaining and Nonces to achieve absolute cryptographic security.","explanation":[{"type":"heading","content":"Modes of Operation in Block Ciphers"},{"type":"paragraph","content":"A block cipher (like AES) mathematically encrypts a strictly fixed 128-bit block of data. However, real-world files are Gigabytes in size. To encrypt a massive file, the data must be violently chopped into 128-bit blocks, and a \"Mode of Operation\" defines the exact mathematical architecture for processing these sequential blocks."},{"type":"subheading","content":"1. Electronic Codebook (ECB)"},{"type":"list","items":["**Mechanism:** The most primitive architecture. Every single 128-bit block is encrypted completely independently using the exact same Key.","**Catastrophic Flaw:** If Block 1 and Block 5 contain the exact same plaintext (e.g., a background color in an image), ECB will mathematically output the EXACT same ciphertext for both blocks. Hackers can visually see patterns in the encrypted data. It is absolutely forbidden in modern security."]},{"type":"subheading","content":"2. Cipher Block Chaining (CBC)"},{"type":"list","items":["**Mechanism:** Absolute mathematical chaining. Before Plaintext Block 2 is encrypted, it is violently XORed with the Ciphertext of Block 1. This creates a massive mathematical cascade.","**Initialization Vector (IV):** Since Block 1 has no previous block, it is XORed with a random IV.","**Merit:** If two blocks have identical plaintext, their ciphertexts will be completely different because the previous ciphertext alters the math. It completely destroys data patterns."]},{"type":"subheading","content":"3. Counter (CTR)"},{"type":"list","items":["**Mechanism:** It completely abandons the traditional block cipher approach and turns AES into a Stream Cipher. It encrypts a mathematically incrementing Counter (Nonce + 1, Nonce + 2) to generate a Keystream.","**Execution:** The raw Plaintext is simply violently XORed with this generated Keystream.","**Merit:** Explosive performance. Because the blocks do not depend on each other (unlike CBC), CTR mode can be mathematically processed in parallel across massive multi-core CPUs."]}]}},{"id":"v2-information-system-security-2021-pB-q5","number":15,"marks":4,"tags":["Part B"],"text":[{"type":"paragraph","content":"Discuss the architecture of IPSec."}],"answer":{"summary":"A critical review of the IPSec architecture. Explains how the Authentication Header (AH) and Encapsulating Security Payload (ESP) protocols violently secure the OSI Network Layer across Transport and Tunnel modes.","explanation":[{"type":"heading","content":"The Architecture of Internet Protocol Security (IPSec)"},{"type":"paragraph","content":"IPSec is a massive, highly complex suite of protocols designed to mathematically secure communications at the absolute Network Layer (Layer 3) of the OSI model. Unlike SSL/TLS which only protects a single browser tab, IPSec violently intercepts every single IP packet leaving the machine and encrypts it, providing invisible, mandatory security to all applications."},{"type":"heading","content":"The Two Core Protocols"},{"type":"list","items":["**1. Authentication Header (AH):** This protocol provides absolute Data Integrity and Data Origin Authentication. It mathematically calculates a MAC (Message Authentication Code) over the entire IP packet (including the headers). It violently prevents hackers from spoofing IP addresses, but it provides ZERO Confidentiality. The data is still sent in plaintext.","**2. Encapsulating Security Payload (ESP):** The absolute workhorse of IPSec. ESP provides Data Confidentiality by aggressively encrypting the payload (using AES-256). It also provides Integrity (via hashing), but unlike AH, it does not authenticate the outermost IP header."]},{"type":"heading","content":"The Two Execution Modes"},{"type":"list","items":["**Transport Mode:** Used strictly for Host-to-Host communication. The ESP header is violently injected *between* the original IP header and the TCP payload. The original IP header remains visible so routers can move the packet, but the payload is mathematically locked.","**Tunnel Mode:** The absolute foundation of Site-to-Site VPNs. The ENTIRE original IP packet (Payload + IP Header) is violently encrypted. A completely NEW outer IP header is attached. This provides absolute security because hackers cannot even see the internal IP addresses communicating inside the tunnel."]}]}},{"id":"v2-information-system-security-2021-pB-q6","number":16,"marks":4,"tags":["Part B"],"text":[{"type":"paragraph","content":"What is an Intrusion Detection System (IDS)? Explain its types."}],"answer":{"summary":"An architectural breakdown of Intrusion Detection Systems (IDS). Details the mathematical anomaly detection engines and contrasts the global surveillance of Network-based IDS against the kernel-level precision of Host-based IDS.","explanation":[{"type":"heading","content":"Intrusion Detection System (IDS) Architecture"},{"type":"paragraph","content":"A Firewall is a dumb architectural wall; it blindly blocks port 22 and allows port 80. An **Intrusion Detection System (IDS)** is the highly intelligent security camera. It mathematically analyzes the raw packets that the firewall allowed through, violently searching for malicious signatures or behavioral anomalies that indicate a hacker has breached the perimeter."},{"type":"heading","content":"Types of IDS Deployments"},{"type":"subheading","content":"1. Network-Based IDS (NIDS)"},{"type":"list","items":["**Architecture:** A dedicated hardware appliance physically attached to a core network switch using a SPAN or Mirror port.","**Mechanism:** It operates in promiscuous mode, silently and violently copying every single packet crossing the entire corporate network.","**Merits & Demerits:** It provides massive global visibility across thousands of computers. However, if the hacker uses HTTPS, the NIDS mathematically fails because it cannot decrypt the AES ciphertext to see the payload."]},{"type":"subheading","content":"2. Host-Based IDS (HIDS)"},{"type":"list","items":["**Architecture:** Aggressive software agents physically installed directly onto the Operating System of critical servers.","**Mechanism:** It ignores network packets. It mathematically analyzes OS Kernel system calls, monitors CPU spikes, and violently checks the cryptographic hashes of critical system binaries (like `login.exe`) to detect unauthorized modifications.","**Merits & Demerits:** Absolute precision. It can see the data *after* it has been decrypted by the server. However, it causes horrific administrative overhead to deploy across 10,000 servers."]}]}},{"id":"v2-information-system-security-2021-pB-q7","number":17,"marks":4,"tags":["Part B"],"text":[{"type":"paragraph","content":"Explain Cross-Site Scripting (XSS) and how it can be prevented."}],"answer":{"summary":"A rigorous exposition on Cross-Site Scripting (XSS) attacks. Explains how attackers violently inject malicious JavaScript into trusted websites, and details the strict mathematical countermeasures of Output Encoding and Content Security Policy (CSP).","explanation":[{"type":"heading","content":"Cross-Site Scripting (XSS) Architecture"},{"type":"paragraph","content":"XSS is a catastrophic web vulnerability that occurs when a web application takes untrusted human input and blindly reflects it back onto a webpage without mathematical sanitization. The attacker violently bypasses backend database security by attacking the victim's browser directly."},{"type":"subheading","content":"The Attack Mechanism (Stored XSS)"},{"type":"list","items":["1. An attacker visits a banking forum and leaves a comment: ``.","2. The bank's database blindly stores this raw text.","3. A legitimate victim logs into the bank and visits the forum.","4. The victim's browser downloads the HTML. When it hits the `

Q3Information System Security

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