
Instructor  Dominique Unruh 
TA  RaulMartin Rebane (submit homework solutions here) 
Lecture Period  February 7  May 24 
Lectures  Mondays, 12:1513:45, Δ2045 + online
(Dominique; may sometimes be switched with tutorial) 
Practice sessions 
Tuesdays, 14:1515:45, Δ1019 (RaulMartin) 
Chat  https://zulip.cs.ut.ee/#narrow/stream/14QuantumCryptography.202022 
Course Material  Lecture
notes (old ones), blackboard photos, practice blackboard photos, and exam study guide. 
Language  English 
Exam  20220609, 14.00–17.00, Delta, room 2039 
Contact  Dominique Unruh <<surname>at ut dot ee> 
Date  Summary  Knowlets covered  Materials 

Feb 07  Quantum systems, quantum states  QState  Video, Whiteboard 
Feb 08  Unitary operations, measurements in computational basis, ElitzurVaidman bomb tester, complete measurements  UniTrafo, CBMeas, PauliX, PauliY, PauliZ, Bomb, ComplMeas  Video, Whiteboard 
Feb 14  Projective measurements.  ProjMeas, ProjMeasVS  Video, Whiteboard 
Feb 15  Quantum Zeno effect, polarization invariant under rotation.  
Feb 21  Tensor product. Composition of quantum systems / quantum states / unitaries / measurements.  ComposQSys, ComposQState, Tensor, ComposUni, ComposMeas  Video, Whiteboard 
Feb 22  Quantum teleportation, Deutsch's algorithm  Deutsch, CNOT, Hada  Whiteboard 
Feb 28  Quantum state probability distributions (ensembles). Operations on quantum state probability distributions. Density operators. Operations on density operators. Theorem: Physically indistinsuishable iff same density operator.  QDistr, PhysInd, QDistrU, QDistrX, QDistrM, Density, Density, DensityU, DensityM, DensityX, DensityPhysInd  Video, Whiteboard 
Mar 01  Backwards toy crypto, implementing boolean unitaries, observables.  Density  Whiteboard 
Mar 07  Quantum OneTime Pad. Partial Trace.  QOTP, ParTr  Video, Whiteboard 
Mar 08  Calculating Partial Trace, Indistinguishability of Global Phase, Tracing out buffer qubits in $U_f$  ParTr  
Mar 14  Partial Trace (continued). Quantum OneTime Pad revisited. Quantum operations. Motivation for trace distance. Statistical distance.  QOTP, ParTr, QOper, QOperAlt, SD, SDSumDef, SDProps  Video, Whiteboard 
Mar 15  Finding Kraus operators for basic operations. Statistical distance of OTP with no zero key.  QOper, ParTr, SD, SDSumDef  
Mar 21  Trace distance. Not in lecture notes: Optimal distinguisher  TD, TDMaxDef, TDSD, TDProps  Video, Whiteboard 
Mar 22  TD between distributions, TD between any two states, QOTP without 0keys.  SD, SDSumDef, TD, TDProps  Whiteboard 
Mar 28  Quantum key distribution: Intro. Security definition. Protocol overview. First step (distributing Bell pairs).  QKDIntro, QKDSecDef, QKDProto, Bell, TildeNotation  Video, Whiteboard 
Mar 29  Prob. of measuring key after QKD. Alternate sec def of QKD. SMT from QKD.  QKDSecDef  Whiteboard 
Apr 04  Quantum key distribution: Bell test. Measuring the raw key.  BellTest, BellTestAna, RawKey, RawKeyKeyDiff, RawKeyGuess, MinEnt, RawKeyEnt, RawKeyAna  Video, Whiteboard 
Apr 05  Measuring the key with t errors.  QKDSecDef, RawKeyGuess  Whiteboard 
Apr 11  Error correcting codes. Error correction step in QKD. Strong randomness extractors. Universal hash functions. Privacy amplification in QKD. Finished QKD security proof.  ECC, QKDCorr, Chain, QKDCorrAna, PrivAmp, RandExtQ, UHF, LHL, PrivAmpAna, QKDWrapup  Video, Whiteboard 
Apr 18  Shor's algorithm. Period finding. Factoring. Discrete logarithm.  Fact, Period, FactFromPeriod, DFT, DFTAlgo, Shor, DlogAlgo  Video, Whiteboard 
Apr 19  Implementing the Quantum Fourier Transform. The von Neumann extractor.  DFTAlgo  Whiteboard 
Apr 25  LWE problem (computational and decisional). Regev's cryptosystem. INDCPA security of Regev's cryptosystem.  BinCompLWE, CompLWE, DecLWE, Regev, RegevCPA  Video, Whiteboard 
Apr 26  Example of Regev's cryptosystem. The Short Integer Solutions problem. CollisionResistant hash functions from SIS.  Regev  Whiteboard 
May 02  Classical/quantum zero knowledge. Difficulty with rewinding in the quantum case.  ProofSys, ZK, GIZK, QZK, QZKProblem  Video, Whiteboard 
May 03  Aborting simulators  classical and quantum.  ProofSys, ZK, GIZK, QZK, QAbortSim  Whiteboard 
May 09  Quantum rewinding. Constructing a quantum ZK simulator.  QRewind, QZKAna  Video, Whiteboard 
May 10  Zero Knowledge: Graph nonisomorphism, Hamiltonian cycles protocol, Schnorr's protocol.  ProofSys, ZK, GIZK, QZK  
May 16  Commitment: Definitions. Impossibility of informationtheoretically secure commitment.  Video, Whiteboard  
May 17  Commitment protocol example, impossibility of it being perfectly binding and hiding.  Whiteboard  
May 23  Schrödinger equation. Particle in an infinite potential well.  Physical  Video, Whiteboard 
May 24  Solving the practice exam.  QState, UniTrafo, ComplMeas, QDistr, Density, PhysInd, ParTr  Whiteboard 
Out  Due  Homework  Solution 

20220225  20210304  Homework 1  Solution 1 
20220302  20220310  Homework 2  Solution 2 
20220311  20220318  Homework 3  Solution 3 
20220318  20220325  Homework 4  Solution 4 
20220330  20220406  Homework 5  Solution 5 
20220418  20220426  Homework 6  Solution 6 
20220425  20220503  Homework 7  Solution 7 
20220511  20220518  Homework 8  Solution 8 
20220527  20220503  Homework 9 
In quantum cryptography we use quantum
mechanical effects to construct secure protocols. The paradoxical
nature of quantum mechanics allows for constructions that solve
problems known to be impossible without quantum mechanics. This lecture
gives an introduction into this fascinating area.
Possible topics include:
You need no prior knowledge of quantum mechanics. You should have heard some introductory lecture on cryptography. You should enjoy math and have a sound understanding of linear algebra.
[NC00] Nielsen, Chuang. "Quantum Computation and Quantum Information" Cambridge University Press, 2000. A standard textbook on quantum information and quantum computing. Also contains some quantum cryptography.
Further
reading may be suggested during the
course. See the "further reading" paragraphs in the lecture notes.