Computer Science Foundations

Cybersecurity and Cryptography Homework Help

Symmetric and asymmetric ciphers, hash function analysis, TLS 1.3 handshakes, vulnerability exploitation in pwnable lab environments, and secure-coding patches. A commonly graded crypto-lab failure is reusing an AES-CBC initialization vector across two messages, the leak our tutors annotate with the exact xor-of-plaintexts attack. Verified CS graduates, starting at $20 per task, 12-hour average turnaround.

Get Cybersecurity and Cryptography Help How It Works
Cybersecurity and Cryptography concept visualization
4 Verified Tutors PhD + MS CS
3,550+ Assignments Solved
12hr Avg Turnaround
98% Satisfaction

Why Cybersecurity and Cryptography

Cybersecurity and Cryptography Homework Help in plain English

Security sits at the adversarial edge of every other CS subject. Cryptography turns data structures into ciphertext, networks into authenticated channels, operating systems into sandboxed execution environments, and software engineering into a discipline of input validation and least privilege.

Topics covered

What we tutor in Cybersecurity and Cryptography

Symmetric Ciphers (AES, ChaCha20)

Symmetric Ciphers (AES, ChaCha20) in Cybersecurity and Cryptography: implementation patterns, named pitfalls, and the autograder cases that catch them.

AES Modes (ECB, CBC, CTR, GCM)

AES Modes (ECB, CBC, CTR, GCM) in Cybersecurity and Cryptography: implementation patterns, named pitfalls, and the autograder cases that catch them.

Public-Key Cryptography (RSA, ECC)

Public-Key Cryptography (RSA, ECC) in Cybersecurity and Cryptography: implementation patterns, named pitfalls, and the autograder cases that catch them.

Diffie-Hellman Key Exchange

Diffie-Hellman Key Exchange in Cybersecurity and Cryptography: implementation patterns, named pitfalls, and the autograder cases that catch them.

Hash Functions (SHA-256, SHA-3, BLAKE3)

Hash Functions (SHA-256, SHA-3, BLAKE3) in Cybersecurity and Cryptography: implementation patterns, named pitfalls, and the autograder cases that catch them.

MAC and HMAC

MAC and HMAC in Cybersecurity and Cryptography: implementation patterns, named pitfalls, and the autograder cases that catch them.

Related

Pair Cybersecurity and Cryptography with

CC++PythonJavaScript

Full overview

Cybersecurity and Cryptography at the university level

Security sits at the adversarial edge of every other CS subject. Cryptography turns data structures into ciphertext, networks into authenticated channels, operating systems into sandboxed execution environments, and software engineering into a discipline of input validation and least privilege. Standard cybersecurity courses cover 8 named topic areas: classical and modern symmetric ciphers (DES, 3DES, AES with ECB, CBC, CTR, GCM modes), public-key cryptography (RSA, ElGamal, ECC over P-256 and Curve25519), hash functions and MACs (SHA-256, SHA-3, HMAC, Poly1305), authenticated key exchange (Diffie-Hellman, TLS 1.3 handshake, signal protocol), web vulnerabilities (XSS, CSRF, SQL injection, SSRF, deserialization), binary exploitation (stack overflow, return-oriented programming, heap exploitation, format string bugs), authentication and access control (passwords, MFA, OAuth 2.0, capability systems), and applied cryptography pitfalls (IV reuse, padding oracle, timing attacks, weak randomness).

A typical security course spends 13 to 15 weeks on these topics with Boneh-Shoup or Katz-Lindell for crypto theory and Stamp or Anderson for systems security. The teaching format splits roughly 50-50 between homework problem sets (proof-based crypto questions, hash collision analysis, attack-scenario reasoning) and hands-on labs (Capture the Flag binaries, pwnable challenges, web exploitation labs hosted on platforms like picoCTF, OverTheWire, and HackTheBox). Hands-on security courses ship a multi-project sequence covering buffer overflow exploitation, return-oriented programming with pwntools, web XSS plus CSRF, side-channel timing attacks, malware analysis, and a network security capstone.

Theory-leaning crypto courses grade cryptographic constructions against the IND-CPA and IND-CCA security games. Combined courses cover both crypto and systems security with a Capture the Flag final project. CSHH tutor matching for this subject draws from CS graduates with split backgrounds: former CTF competitors with binary-exploitation depth for the pwnable and reverse-engineering labs, plus formally-trained cryptographers comfortable with reduction-based security proofs for the theory side.

Our tutors deliver attack walkthroughs with exploit scripts in Python or pwntools, defense patches with explicit threat models, cryptographic implementations using libsodium or pyca/cryptography (never homemade primitives in production), and security analyses framed against the relevant attacker model. Languages supported: C and C++ for binary exploitation labs, Python for cryptographic protocols and CTF scripting, JavaScript for web vulnerability assignments.

Where Students Get Stuck

Why students struggle with Cybersecurity and Cryptography

AES mode selection and IV management

ECB leaks structure (the classic Tux penguin demo), CBC requires unpredictable IV plus separate MAC, CTR is stream-cipher style requiring unique nonce, GCM authenticates and encrypts in one pass but reuses nonce catastrophically. We pick GCM for new code, document the nonce-uniqueness invariant explicitly, and use a 96-bit random nonce or a 64-bit counter with strict atomicity guarantees.

RSA padding and small-exponent attacks

Textbook RSA (no padding) suffers chosen-ciphertext attacks, small-message attacks with e equal to 3, and broadcast attacks across 3 different moduli. PKCS#1 v1.5 padding leaks Bleichenbacher oracle. OAEP padding is the textbook fix; RSA-PSS for signatures. We implement using pyca/cryptography or libsodium primitives, never raw modular exponentiation in production code.

Stack canary, NX, ASLR, PIE bypass selection

Run checksec first to identify the active mitigations. No canary plus no NX permits classic shellcode injection. NX without ASLR permits ret2libc with known libc address. ASLR without PIE permits partial-overwrite or GOT-leak techniques. Full PIE plus ASLR plus stack canary requires an info leak (format string or out-of-bounds read) to derandomize before ROP can land. We document the bypass chain in the exploit script.

Return-oriented programming (ROP) chain construction

Find useful gadgets with ROPgadget or ropper, chain them to set up syscall arguments (rdi, rsi, rdx for x86-64 syscall ABI), then invoke a syscall (typically execve("/bin/sh", 0, 0)). pwntools simplifies offset calculation and chain assembly. We build ROP chains targeting libc when the binary itself lacks useful gadgets.

Padding oracle on AES-CBC

A server that returns distinguishable responses for "bad padding" vs "bad MAC" leaks 1 bit per query. With 128 to 256 queries per byte, an attacker decrypts arbitrary CBC ciphertext. The fix: encrypt-then-MAC with constant-time MAC verification, or use AES-GCM. We provide the attack script in Python plus the patched server with HMAC-SHA256 in constant time.

XSS, CSRF, and SQL injection chained defenses

Content-Security-Policy with nonce-based inline scripts prevents reflected XSS. SameSite=Lax cookies plus CSRF tokens prevent state-changing CSRF. Parameterized queries via psycopg2 or SQLAlchemy ORM prevent SQL injection. Each defense covers a distinct attack class; we layer all 3 with explicit policy headers and a 1-page memo on the assumed attacker capabilities.

Assignment Types

Cybersecurity and Cryptography assignment types we cover

Symmetric cipher and AES-mode tasks

AES in ECB, CBC, CTR, and GCM with IV and nonce management and library-backed primitives. Named pitfall: reusing a GCM nonce across two messages, which leaks the authentication key and forges arbitrary ciphertext.

Public-key crypto and RSA attacks

RSA key generation, OAEP encryption, and PSS signatures plus small-exponent and padding-oracle attack analysis. Named pitfall: textbook RSA with e equal to 3 on a short message, recoverable by a plain cube root with no modular reduction.

Binary exploitation labs

Stack smashing, ret2libc, and ROP chains built with pwntools after a checksec mitigation survey. Named pitfall: skipping the info leak under full ASLR and PIE, so the ROP chain lands on a randomized address and crashes.

Web vulnerability assignments

XSS, CSRF, SQL injection, and SSRF exploitation paired with layered defenses (CSP, SameSite cookies, parameterized queries). Named pitfall: blocklist input filtering that a single encoding variant slips past, leaving the injection open.

Padding-oracle and protocol attacks

AES-CBC padding-oracle decryption, hash length-extension, and authentication-protocol analysis under an active attacker. Named pitfall: a server that returns distinct errors for bad padding versus bad MAC, leaking one plaintext bit per query.

Crypto proofs and CTF challenges

Reduction-based IND-CPA and EUF-CMA proofs plus Capture the Flag work across web, pwn, crypto, and reverse-engineering. Named pitfall: a strcmp token comparison that returns early on the first mismatch, leaking the matching prefix through timing.

TLS, authentication, and secure-coding patches

TLS 1.3 handshake analysis, password hashing with Argon2id, OAuth 2.0 flows, and threat-modeled defense patches. Named pitfall: JWT algorithm confusion (alg=none or RS256 verified as HS256), which lets an attacker forge a valid token.

Tutors Who Cover This Subject

Verified Cybersecurity and Cryptography tutors

FAQ

Cybersecurity and Cryptography help, frequently asked

Can you help with AES and block cipher modes?
Yes. AES in ECB, CBC, CTR, and GCM modes with the security tradeoffs documented per mode. ECB is for teaching only (we show the Tux penguin demo). CBC requires unpredictable IV plus separate MAC. CTR is the stream-cipher mode requiring unique nonce. GCM combines encryption and authentication in one pass. Implementations use pyca/cryptography or libsodium, never raw AES rounds for production code. The deliverable includes test vectors from NIST SP 800-38A.
Do you help with RSA implementation and attacks?
Yes. Key generation with safe primes via Miller-Rabin primality testing (40 rounds for cryptographic confidence). Encryption with OAEP padding. Signatures with RSA-PSS. Common attacks covered: Bleichenbacher (PKCS#1 v1.5 padding oracle), Coppersmith (small exponent with known plaintext bits), Wiener (small private exponent under 1/3 of N to the 1/4), broadcast attack (same message encrypted to 3 recipients with e=3). We use pyca/cryptography for production-style code.
Can you help with buffer overflow and exploitation labs?
Yes. Classic stack-smashing for control-flow hijack, ret2win for finding a useful function already in the binary, ret2libc for invoking system("/bin/sh") with a libc address, return-oriented programming for chaining gadgets when NX is enabled, sigreturn-oriented programming for systems without useful gadgets. Exploits in pwntools with explicit offset calculations and ASLR brute-force or info-leak chains where applicable.
Do you cover web vulnerabilities (XSS, CSRF, SQL injection)?
Yes. Reflected and stored XSS exploitation, with Content-Security-Policy nonce-based defense. CSRF exploitation via auto-submitting forms, with SameSite=Lax or Strict cookies plus token-based defense. SQL injection via UNION-based extraction, blind boolean-based extraction, and time-based extraction, with parameterized queries via psycopg2 or SQLAlchemy as the defense. Server-side request forgery (SSRF) and insecure deserialization with Pickle or Java Serialization also covered.
How fast is cybersecurity homework delivered?
12-hour average for problem sets, CTF challenges, and security analyses. Larger projects (full exploit chain, custom cryptographic protocol implementation) typically 24 to 72 hours given the research and testing time. Rush 4 to 6 hours for single-question pwnable challenges for an additional fee. Pricing: $20 Debug and Explain per task, $30 Full Solution per task, $40 per hour Live Tutoring. All exploits come with the working script, the vulnerability analysis, and the defense recommendation.
Do you help with TLS analysis and PKI assignments?
Yes. TLS 1.2 handshake (ClientHello, ServerHello, Certificate, ServerKeyExchange, ClientKeyExchange, ChangeCipherSpec, Finished) and TLS 1.3 simplified 1-RTT handshake with ECDHE forward secrecy. Certificate validation: signature verification with the chain to a trusted root, hostname matching with SNI, revocation checking via OCSP stapling or CRL. Common attacks covered: BEAST, CRIME, POODLE, Heartbleed, FREAK, Logjam, with the corresponding RFC mitigation explained.
Can you help with CTF challenges (picoCTF, HackTheBox, OverTheWire)?
Yes. We solve and explain challenges across the standard categories: web (XSS, SQLi, IDOR, SSRF), pwn (buffer overflow, ROP, heap exploitation), crypto (padding oracle, RSA attacks, hash length extension), reverse engineering (Ghidra and IDA Pro static analysis, gdb dynamic analysis, anti-debugging bypass), forensics (file carving, memory analysis with Volatility, network capture analysis with Wireshark and Zeek). Writeups include the methodology, the discovered vulnerability, and the exploit script.
Do you cover authentication and access control?
Yes. Password storage with bcrypt or Argon2id (never plain SHA-256 or MD5). Multi-factor authentication with TOTP (RFC 6238) or WebAuthn (FIDO2). OAuth 2.0 authorization code flow with PKCE, refresh token rotation, and explicit scope minimization. OpenID Connect identity layer on top of OAuth 2.0. Capability-based access control with bearer tokens or HMAC-signed credentials. Common pitfalls: timing-attack-vulnerable token comparison, insufficient entropy in token generation, JWT algorithm confusion (alg=none, RS256 vs HS256 key confusion).
Can you help with secure coding patches?
Yes. Input validation with allowlist patterns rather than blocklist. Output encoding context-aware per sink (HTML entity for HTML, JavaScript escape for JS, URL encode for URLs). Constant-time comparison for any secret-dependent value (hmac.compare_digest, CRYPTO_memcmp). Memory safety via std::vector and std::string in C++ instead of raw arrays, or rewrite in Rust where the assignment permits. Each patch includes the threat model, the original vulnerability, the patch, and a 1-page memo on residual risk.
Do you help with cryptographic protocol design and proofs?
Yes. Authentication protocols (Needham-Schroeder, Kerberos, signal protocol) analyzed against active attackers per Dolev-Yao threat model. Security reductions for symmetric encryption (IND-CPA, IND-CCA), for MACs (EUF-CMA), for signature schemes (EUF-CMA). The proofs follow the game-hopping methodology from Boneh-Shoup. We write proofs in numbered steps with each game transition justified by a concrete bound on the distinguishing advantage. ProVerif or Tamarin for automated protocol verification on advanced assignments.
Can you help with penetration testing assignments?
Yes. Reconnaissance with nmap (TCP SYN scan, version detection, OS fingerprinting), Shodan or Censys for external-facing service enumeration, dirb or gobuster for web directory discovery. Exploitation with Metasploit modules for known CVEs, manual exploitation for novel vulnerabilities, post-exploitation with Meterpreter for pivoting. Reporting follows the PTES standard (executive summary, methodology, findings with CVSS scores, remediation recommendations). We never deliver active exploitation against systems the student does not own; the work targets explicitly-authorized lab environments only.

Explore related areas

Need Cybersecurity and Cryptography Help?

Submit your assignment and get matched with a verified Cybersecurity and Cryptography tutor in 15 minutes.

Submit Your Assignment