JAIST Repository
https://dspace.jaist.ac.jp/Title

Information Security for Privacy Protection

Author(s)Miyaji, Atsuko

CitationIssue Date

2005‑03‑11

TypePresentation

Text version

publisher

URL

http://hdl.handle.net/10119/8274

RightsDescription

JAIST 21世紀COEシンポジウム2005「検証進化可能電子社会」 = JAIST 21st Century COE Symposium 2005
Verifiable and Evolvable e‑Society , 開催：2005年3月10日〜11日, 開催場所：石川ハイテク交流センター, Technical session 3 <Security>

Japan Advanced Institute of Science and Technology

Abstract

MIYAJI LABInformation Security for Privacy Protection• How and Why our privacy has been leaked out?
• What is a solution to protect our privacy?
ÆInformation Security• Recent research interest on information security to enhance
our privacy.

Atsuko MiyajiJAIST2Outline

MIYAJI LAB

Our life has been degitalized

MIYAJI LABVISAShop••••Our life has been degitalized.
Our privacy has been leaked out.
Subjects of Information Security.
Recent research of information security– Protect your system even if your key has been stolen– Protect your key against electronic consumption– Protect your privacy against collusion

Go to a shop.

SSL

IC CardInternet
Use internet

Hospital

RFID
12AXX
12AXXBorrow a book with RFID
3MIYAJI LAB

Our privacy has been leaked out

MIYAJI LAB

It seems secure by encryption.
Theoretical security analysis is necessary.
Fault tolerance system is required: it stands if a key is stolen.
Shop

Go to Hospital with a book

4

Our privacy has been leaked out

It seems secure: IC card, secure number theory, never stolen
the card, and face-to-face communication without Internet.
Realistic security analysis is necessary: implementation

VISA
VISA

Direct Attack

InternetUse internet

SSL

Indirect Attack
Your key has been stolen.

Go to a shopThe algorithm has
been already broken
such as SHA1.

Indirect Attack
Side-channel attack
Your key has beenstolen by analyzing
power consumption.

IC CardYour privacy has
been leaked out
without awareness!!
5Your privacy has
been leaked out
without awareness!!
61

MIYAJI LAB

Our privacy has been leaked out

MIYAJI LAB

It seems secure through secure channel.
Anonymity is necessary for protocol.
VISA

Shop

SSL

Privacy information has expanded: location, taste, opinion,
idea…
Unlink-ability is necessary for protocol.

Alice needs
insurance.

Alico

She ishere!

Internet

Alice
Ski
No insurance

Our privacy has been leaked out

Indirect Attack

12AXX
HospitalYour various privacy
has been gathered
and combined.

linkable

RFID

Serial No
12AXX

Borrow a book with an RFID

linkable

Go to Hospital with the book
Hospital

Alice
CancerMild

12AXX

Your privacy has
been leaked out
without awareness!!7

What shall we do?

MIYAJI LAB

Fault tolerant system-key-evolving system

Minimize the damage when a secret key is lost or broken.

Secure network modeling
analysis the security relatedwith network or software.

•mobile agent•network virus•RFID security

Secure electronic protocol
provide enhanced secure
electronic protocol: anonymity,
unlink-ability, lost-key security
Cryptographic basic researchanalysis security & efficiency
Side-channel attack•A secret key is divided into two devices, user and base.
•Key evolution over time is achieved by user and base.
•User and base are exposed repeatedly
Î Any user key except those exposed user keys remains
secure.
exposed•Public-key
encryption•Secret-key
encryption

base

userSecurity Integration
VISA

Shop+*?/SkiMIYAJI LAB

SCA-resistance

Provable secure enc.,
Key evolving enc

AnonymityGroup signature

securesbkt-1sbkt

sbkt+1

skt-1

skt

skt+1

secure10Concluding Remarks• We have seen how our privacy has been leaked out
without awareness.

• We will give a way that user can control her/his privacy
level: sometimes link-ability is fine.
• We will provide the minimum integration that enhancevarious system security.

HospitalX+**>
Cancersk0sbki• We have shown that information security protect ourprivacy.

IC CardInternetsbk0

exposed

9MIYAJI LABYour simple privacy such as
location, idea, taste, etc has been
leaked out without awareness!!
8MIYAJI LAB

We need information security !

•Groupsignature•E-money•E-auction•Faulttolerance

You just have a bookwith a RFID.

Unlinkability
12AXX

Secure RFID

12AXX

RFID
11122