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Dokumenty

Výuka

Kontakt a konzultačné hodiny

adresa: Katedra informatiky, FMFI UK, Mlynská dolina, 842 48 Bratislava
miestnosť: M-214
e-mail: stanek@dcs.fmph.uniba.sk
telefón: (+421 2) 60295 101

Konzultačné hodiny: dohodou

Dokumenty

Dokumenty o kryptológii určené viac-menej laikom (vopred ďakujem za ľubovoľné pripomienky k obsahu alebo forme):

  1. Kryptológia (23 strán): pdf, verzia 2b, 2020
  2. Kryptológia II (30 strán): pdf, verzia 2b, 2020

Výuka ZS 2023/24

Diplomový seminár (3) (Str 11:30-13:00 M-V)

Kryptológia 1 (Str 16:30-18:00 M-II, Štv 16:30-18:00 M-II)

Slidy zo ZS 2023/24: archív

Lectures:

  1. Introduction - about, intro
  2. Cryptanalysis of simple ciphers - slides, examples: substitution cipher, Vigenere cipher
  3. Block ciphers: slides 1; slides 2
  4. Stream ciphers - slides
  5. Public-key cryptography - introduction - slides
  6. RSA scheme (correctness and implementation) - slides
  7. Security of the RSA - slides
  8. Discrete logarithm and related schemes - slides
  9. Exercise 1 - EN, SK
  10. Hash functions - slides
  11. Massage authentication codes - slides
  12. Passwords - slides
  13. HOTP and TOTP - slides
  14. Digital signature schemes - slides
  15. Hash-based signatures - slides
  16. Introduction to LWE - slides
  17. Code-based encryption schemes - slides
  18. Exercise 2 - EN, SK
  19. Cryptographic protocols - introduction - slides

Homework assignments (students):

  1. Find the plaintext for given ciphertexts. The ciphertexts were produced by the following Python script, using a variant of one-time pad cipher: hw1.py. The plaintexts are quotes in English language. Each plaintext was encrypted three times, producing three ciphertexts cipherA, cipherB, and cipherC (each time an independent key was used). Please, send your solution by e-mail with subject "Cryptology (1) - homework 1" containing: (1) plaintext that makes sense, (2) short description of your solution, and (3) the source code used for analysis.
    Ciphertexts: zip
    Deadline: 23/10/2024 at midnight
  2. Find the plaintext m given ElGamal public parameters (p, g, y), and 16 independent encryptions of texts m, m+1, m+2, ..., m+15. The ciphertexts have form (r,s), see the lecture for details. You have an additional information that m is from the set {2^{987}, 2^{987}+1, ..., 2^{987}+4000}. Please, send your solution by e-mail with subject "Cryptology (1) - homework 2" containing: (1) m value, (2) short description of your solution, and (3) the source code used for analysis.
    Input data: zip
    Deadline: 8/11/2024 at midnight
  3. Schnorr signature scheme was modified to use a shady signature computation, see the source code schnorr.py. Knowing a public key and signatures for messages "0", "1", ..., "1023", calculate the corresponding private key x. Please, send your solution by e-mail with subject "Cryptology (1) - homework 3" containing: (1) value of x, (2) short description of your solution, and (3) the source code.
    Input data: zip
    Deadline: 27/11/2024 at midnight