Security Issues in Mobile Communication Systems. N. Asokan. Nokia ... minimize message sizes, number of messages. Increased risk ... service: unforgeability ...
User(pk, M) Sign(sk) s / reject. Verify(pk, M, s) 0/1 ... Tag(K) send pk to user, then execute Sign(sk) User(M) compare received pk to pk' in shared state ...
Digital Signature. Sheng Zhong. 2. Digital Signature (1) Public-key-based technique for data integrity. A digital signature scheme is a tuple (PK, SK, M, S, KG, ...
Certificate Based (Linkable) Ring Signature. Man Ho Au, Willy Susilo, Tsz Hon Yuen ... ID-Based Problem of Key Escrow (Private Key Generator (PKG) is too powerful) ...
Enables a user to obtain a signature from a signer on a message ... Motivation: e-cash, e-voting ... Example: e-cash (simplified) Bank has public key PK. User: ...
Zero-knowledge Interactive Proofs. Interactive Proofs and the ... A goal in itself: Sudoku example. www.wisdom.weizmann.ac.il/~naor/PAPERS/SUDOKU_DEMO ...
e-cash: By circulating information called coin, a payment from a user to a ... coin amount is kept secret, but correctness of amounts of old and new coins is ...
Why do we need payment in Tor? Other payment systems. PAR payment system overview ... Sybil Attack. Recent Developments in Cryptography and Information Security ...
... authority can select h of order q. Key generation: vi = gxi , hi ... Relies on composite order bilinear groups. subgroup decision. strong Diffie-Hellman in Gp ...
Foundations of Privacy Formal Lecture Zero-Knowledge and Deniable Authentication Lecturer: Moni Naor Giving talks Advice on giving Academic Talks Giving an Academic ...
Digital signature in automatic analyses for confidentiality against ... Adversary is active - it schedules the participants and relays messages between them ...
Parallelism. Randomness. Identify problems that are infeasible to compute by any reasonable machine ... Taxonomy: classify problems into classes with similar ...
Responsible Party: ... Birthday paradox requires over 280 unique objects before collisions worrisome ... submitted to Responsible Party which chooses a final ...
Rapid growth of bandwidth in the interior of the net. Broadband to the ... Want: Geographic independence for availability, durability, and ... Like hologram ...
Strongly Universal One-Way Hash. Definition and ... E.g. chopping last bit of input. Consider the (n, n-1)-family G where each g G is defined by h H ...
A signature is a commitment (or binding) of a person to a document. Dear John: ... Output yes if and only if gh'yrrs mod p. 2001/12/26. Network Security. 10 ...
What to do with them: design signature schemes, broadcast authentication, ... Steal money, perform money laundry, obtain insider information, hack into a system. ...
Clock Synchronization Ken Birman Why do clock synchronization? Time-based computations on multiple machines Applications that measure elapsed time Agreeing on ...
An Efficient and Secure Event Signature (EASES) Protocol for ... Play the paper, scissors, rock game remotely without arbiter. 9. Background hash function ...
MPhil Student in CS Department. City University of Hong Kong ... J. Beak, R. Steinfeld, and Y. Zheng. Formal proofs for the security of signcryption. ...
Could break: Bob's signature from one protocol could be used to attack another ... AES based using above keys (Shared Secret-PMK) Laptop. Access Point. Auth Server ...
Vote assist par ordinateur, mais dans un bureau de vote pour le vote ... Votes exclusifs sur syst mes E-Poll : Cremona, Ladispoli, Czestochova, Ladispoli ...
Project 3 is due on Monday Nov. 18th. 4th individual ... Interpreters. Check the execution of. every instruction. Hard to mediate high-level. abstractions ...
Key size dependent on security parameter (e.g. 1024 bits) ... Other efficiency parameters only depend on k. ... bound L. Security parameter k. Secret key size: ...
Why is synchronization so complicated? ... External Clock Synchronization. Synchronize clocks with respect to an external time reference: usually useful in ...
Example: Auctions. Different requirements - different notions. ... If key is used for a single auction and secrecy is not required after the auction is over ...
Rapid growth of bandwidth in the interior of the net. Broadband to the ... Cross-administrative domain. Metric: MOLE OF BYTES (6 1023) OceanStore:4. FDIS 2002 ...
OceanStore. Toward Global-Scale, Self-Repairing, Secure and Persistent ... Rapid growth of bandwidth in the interior of the net. Broadband to ... hologram ...
... and papers of: Schoenmakers, Benaloh, Fiat, Adida, Reynolds, Ryan and Chaum ... Reynolds' Scheme. Voter enters the booth and receives a blank ballot. ...
Current issues of e-cash and Fair tracing. Network Security Term Project ... 2. The Bank checks the signature and if it is valid, credits the Vendor's account ...
Non-Malleable Encryption From Any Semantically Secure One ... Many well-known cryptosystems are easily malleable. GM Encryption: Enc(0) = r2, Enc(1) = yr2. ...
Identification, Authentication and encryption ... Universal one-way functions, multiple identifications, ... Does High Entropy Suffice for Identification? ...