adversarial model
INDistingushability
分辨率
under chosen ciphertext attacks
back up
scheme
IND-CPA encryption
verifiability
schemes considering sa and ND
non-delegatable schemes
pkzip compression algorithm
12 bytes input
bk94
stay in fse01
ciphertext-only attack
PRNG
focus only on his attack algorithm
biham and
bk94 attack process
guess some bit
early step: 6 bits
find some bits of k[1] and kk1[1]
side-channels
relation between
stay01 bk94
synthetic linear analysis
on bias analysis
CubeHash preliminaries
The EVITA hardware Security Module
software layers
meadows
puzzles proof of work
signatures
cookies
rechability
moderately hard puzzles based on this
easy to generate
hard to solve
easy to verify
computation bound or memory bound
former.
tuple of algorithms
puzzle security properties
difficulty
unforgeability: hard for the adversary to generate valid puzzles
non-parallelizability :非常重要
tuneable difficulty
useful puzzles: the work done in solving a puzzle can be used for another target.
HASH-based puzzle (Juels-Brainard)
merits: generation and verification very efficient
time-lock puzzles of Rivest-Shamir-Wagner (RSW)
choose random a
puzzle consists of (n,a,q)
Karame-Capkun puzzle
(ESORIS 2010)
BPV Generator
Pre-processing run once...
whenever a pari .. is needed..
a new non-parallelisable puzzle (RSA puz)
setup genuz findsoln versoln
rsw puz kc puz rsa puz
a new