Your SlideShare is downloading. ×
0
Juno [u∶no∶]
draw passwords
연세대학교 수학과 설진석
Abstract
•

alternative cryptographic hash function
•

image based

•

using Life-Like Cellular Automata

•

algorithm dev...
Preliminaries
•

Classical Mathematics

•

Automata Theory
Cryptographic
Hash Function
•

given a function f: X → H, H = L(w{n})

•

f is called cryptographic hash function if
•
•

...
Cellular Automata
•

In n dimensional grid, given a
•
•

T : transition rule

•
•

S : set of states

B : neighbor

Each c...
one-dimensional
CA example

•

each row denotes step

•

each column denotes cell’s
state history
Life-Like
Cellular Automata
•

In two-dimensional grid
•

S : “alive” or “dead”

•

T : “survive”, “birth”, or “death” det...
LLCA example:
Conway’s Game of Life
•

rule string B3/S23

•

A cell survives if 2 or 3
neighbor is alive, and births if
2...
Object
•

drawing password, rather than inserting string

•

using LLCA as cryptographic hash function
Algorithm

Raw Drawing

Simplify

Encode

Hash via LLCA
Encoding
1
0
0
0
1

Original

0
1
0
0
1

0
1
0
0
0

0
0
1
1
1

Binary

8611d
Result
fixed sized image = fixed sized string...
LLCA as Hash?
•

LLCA is a function
•

•

CA itself is a deterministic

inverse LLCA is NP
•

checking answer is P

•

usi...
Limitations
•

sparse initial state generates sparse output
•

•

requires minimum alive cells to be meaningful value

inf...
Benefits and Applications
•

At least, it is valid cryptographic hash function

•

Calculation can be parallelized

•

Eas...
Implementation
•

Using coffee-script based LLCA library “Plasmid”
•

•

http://nyamukoong.github.io/plasmid/

Result: htt...
Upcoming SlideShare
Loading in...5
×

Project Juno: Draw passwords!

499

Published on

Simple project for "draw passwords, rather than typing a string". Used Life-Like Cellular Automata for hashing images.

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
499
On Slideshare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
2
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Transcript of "Project Juno: Draw passwords!"

  1. 1. Juno [u∶no∶] draw passwords 연세대학교 수학과 설진석
  2. 2. Abstract • alternative cryptographic hash function • image based • using Life-Like Cellular Automata • algorithm development
  3. 3. Preliminaries • Classical Mathematics • Automata Theory
  4. 4. Cryptographic Hash Function • given a function f: X → H, H = L(w{n}) • f is called cryptographic hash function if • • • Pa, b ∈ X (f(a)=f(b)) ≦ p -1 for ∀h ∈ H, “answering f (h)” is a NP-problem where • X : given set • p : desired probability • n : natural number
  5. 5. Cellular Automata • In n dimensional grid, given a • • T : transition rule • • S : set of states B : neighbor Each cell’s next state is determined by current state of the cell and neighbor applied by transition rule.
  6. 6. one-dimensional CA example • each row denotes step • each column denotes cell’s state history
  7. 7. Life-Like Cellular Automata • In two-dimensional grid • S : “alive” or “dead” • T : “survive”, “birth”, or “death” determined by number of “alive” cells in neighbor • B : Moore neighborhood (adjacent 8 cells)
  8. 8. LLCA example: Conway’s Game of Life • rule string B3/S23 • A cell survives if 2 or 3 neighbor is alive, and births if 2 neighbor is alive. Otherwise, it dies.
  9. 9. Object • drawing password, rather than inserting string • using LLCA as cryptographic hash function
  10. 10. Algorithm Raw Drawing Simplify Encode Hash via LLCA
  11. 11. Encoding 1 0 0 0 1 Original 0 1 0 0 1 0 1 0 0 0 0 0 1 1 1 Binary 8611d Result fixed sized image = fixed sized string 8 6 1 1 d Hex
  12. 12. LLCA as Hash? • LLCA is a function • • CA itself is a deterministic inverse LLCA is NP • checking answer is P • using “number of live neighbors”, so inverse can be calculated with non-deterministic turing machine
  13. 13. Limitations • sparse initial state generates sparse output • • requires minimum alive cells to be meaningful value infeasible to control or calculate collision probability p
  14. 14. Benefits and Applications • At least, it is valid cryptographic hash function • Calculation can be parallelized • Easy to control complexity • • • changing rule string terminating condition Can be used for signature authentication, or fingerprints
  15. 15. Implementation • Using coffee-script based LLCA library “Plasmid” • • http://nyamukoong.github.io/plasmid/ Result: https://theeluwin.kr/juno/
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×