state university of telecommunications line cipher demonstration for educational purposes p.m....
TRANSCRIPT
State University of Telecommunications
Line cipher demonstration for educational purposes
P.M. Tutunnick, [email protected]: D.V. Kushnir
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Outline• Cryptology basics:
– Subject and main directions– Binary functions
• The overview of “Virtual University” complex creation history• Main principles of PC-based laboratory exercise• “LogiCon” experimentation tool introduction:
– Nature and general purpose– Main features list– Engine functionality basics– Interface capablities
• Application example:– “Exploration of Line-Recurrent Register” exercise– Key generator projects contest
• Complex adapation posiblities• Alternative use directions• Progress perspectives
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Cryptology Subject
The science studying principles, methods and means of transformation of the information for its protection against unauthorized access and distortion.
Science about safety of communications
CryptographyThe science studying principles of possible cryptoatacks, and measuring defensive potential of cryptosystems.
Cryptanalysis
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Cryptography directionsIt provides:
• Secrecy of stored private information
• Safety of messaging
• Users autentification
• Security of algorithms
• Passwords & keys management
Objects to protect :
• Encryption and decryption algorithm
• Transmitting channels
• Encryption details
• User co-ordinates
• Fact of encrypted transmittion
Types of important information, that needs to be protected:
• State secret
• Military secret
• Commercial secret
• Jurisprudential Secret
• Medical secret
• etc.
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Tipical Cryptosystem Model
Main Types of Attacks :• Statistical (“linguoanalysis”) attac • Algorithm (“exploit”) attack• Chosen content (“user”) attack• Block-revealing (“vocabulary”) attack• Power (“all-key”) attack• Destructive (“heating”) attack• etc.
• Replacement ciphers
(Lisandr, “Scitala”)
• Switching ciphers
(“Caesar cipher”)
Simple Ciphers:
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Binary Functions
y=F(x1,x2,..xn)Decimal (Multiplexing)
1 2 3 4
1 1 2 3 4
2 2 4 6 8
3 3 6 9 12
4 4 8 12 16
Binary (OR operation)
0 1
0 0 1
1 1 1
x1 y
0 1
1 0
x1 x2 y
0 0 0
0 1 0
1 0 0
1 1 1
x1 x2 y
0 0 0
0 1 1
1 0 1
1 1 1
“NOT” “AND” “OR”Binary Basis 3D Basis
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Basis Functions Combining Example:
“XOR” Operator 1 1 0
0 1 1
1 0 1
0 0 0
y x2 x1
1221 XXXX %50)1|1(%50)1( 22 XYPXP
21 XXY
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“Virtual university” project complex• Started: 1993
• Developed by: teachers and students of SUT ITTERC
• Meant to: assist the educational courses by interactive demonstration of it’s subjects and systematyse already existing thematical computing researches
• Now allows to:– Provide high-quality visual & interactive representings of
described physical & logical processes
– Fully automatyse technicaly aspects of educational processes
– Stimulate new researches by integrating it in earlier application packages
– Complete practical tasks remotely via internet
– Use virtual laboratories for performing topical experiments of any kind without any additional equipment
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Subjects of University, in which project components are employed:
• Cryptography
• Steganography
• Programming on C Language
• Programming on Assembler Language
• High Level Programming
• Computing Support of Engeneering
• ElectroCommunications Theory
• SchemoTechnics Basics
• Digital Processing of Signals
• Military practice
Most of program complexes developed by ITTERC are integrated in the common database system that provides user access, basing on a Smart-Card technology, and contains student practice real-time statistics.
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PC-based practice program properties:
Educational utility Clear work plan Interactive elucidative texts Not too formal and easy to perform Acceptable visualization quality Unified interface functionality Wide experimental capabilities Controling and score-counting tools Integrated client-server system Modification abilities
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Virtual Logical Models Constructor Utilityaka LogiCon
- Multipurposal educational desighning toolset package, that allows to create, redact and analyse fully operational logical schemes of different sorts.
- Was developed in 2004 for demonstration of cryptography basic algorithms.
- Upgraded to provide experience of exploring and development of abstract logic schemes, allowing to applicate it more effectively and widely.
- Is currently bypassing final adaptation and tests before getting into exploitation.
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LogiCon Project main features list
• Flexible logical functionality
• User-friendly interface
• Drag’n’drpop-based workspase
• Rich set of pre-programed logical elements
• Nearly unlimited number of construction blocks
• Blocks flexible tuning ability
• Multi-level logic desighn
• File-level exchange
• Built-in script sublanguage
• Abitity to model occasionaly events
• Statistic analiser tools
• Interactive guiding informer
• Smart result-checking system
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LogiCon Engine functionality basics: “block”
• Input/Output
• Registers
• Functions
• Custom Operators
- Primary construction element
- Low-level defined visual object
- Provides inner data processing
Each kind of element is supported with a individual settings system
with a simple access by a pop-up menu, allowing to change block
options swiftly without replacing it.
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LogiCon Engine functionality basics: “link”
- Single-sided connection between blocks
- Defined as a block logical property
- Delivers the binary calculation results
User-established links define a scheme graph virtual
matrix, allowing it to perform logical operations.
- Standart, constantive state of a scheme
- Untill switched all digital values remain unchanged
Proceeding to the next phase allows to spectate sceme
operating step-by-step and to receive the intermediate
results of process.
LogiCon Engine functionality basics: “phase”
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Logicon Interface Components
System Menu
Desighn Space
Zoom-In/Out
Switch to Next/Previous Phase
Availible Components
Stand-Alone Component
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Block Ciphering Stream (Line) Ciphering
Joining Algorithm
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Simple stream cipher algorithm
Encryption Decryption
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LogiCon representation
Encryption DecryptionTransmission
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Linear recurrent register shift algorithm
T=2n-1
B0,2=F(B2,1,B7,1)
n
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Modified (switching) key generator
T=T1.T2.T3
