Proposal of MISTY1 as a Block Cipher of Cipher Suites in TLS

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Proposal of MISTY1 as a Block Cipher of Cipher
Suites in TLS

• Hirosato Tsuji Toshio Tokita
  Mitsubishi Electric Corporation

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Presentation Agenda

• Block Cipher MISTY1

--- by Toshio Tokita

• Current Status and Next Steps of MISTY1 to
  support TLS

--- by Hirosato Tsuji
3
Block Cipher
MISTY1

• Toshio Tokita
• Mitsubishi Electric Corporation
• MISTY_at_isl.melco.co.jp

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Overview

• Secret-key block cipher

64-bit block, 128-bit key, a variable number of
rounds (8-round recommended)
proposed by M.Matsui (Mitsubishi) in 1996 at Fast
Software Encryption Workshop FSE4

• Widely used in many applications

Governmental applications
Public transportation systems, Secure network
systems, etc,etc
Commercial products
S/MIME E-mail software, VPN(Routers/Hubs),
Encryption LSI, PKI Software services, etc, etc
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Recent News

• KASUMI has been adopted as a mandatory
  algorithm for data confidentiality and data
  integrity in W-CDMA by 3GPP. (March, 2000)
• KASUMI will be also used in current GSM systems
  as an alternative for A5.
• KASUMI is a variant of MISTY1
• designed for W-CDMA systems.
• KASUMIMIST

3GPP 3rd Generation Partnership
Project
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Pointers

• ISO9979 No.13 (algorithm registration)
• URL for Internet-Draft http//www.ietf.org/inter
  net-drafts/draft-ohta-misty1desc-02.txt
• Specifications
• http//www.mitsubishi.com/ghp_japan/misty/mist
  y_e_b.pdf
• Royalty Free License
• http//www.mitsubishi.com/ghp_japan/misty/lice
  nsee.htm
• MISTY1 essential patent is licensed
• under
  royalty free conditions.

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Design Criteria

• High security
• Provable security against differential and linear
  cryptanalysis
• Multi platform
• High speed in both software and hardware
  implementations
• Compact
• Low gate count and low power consumption in
  hardware

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High security

• MISTY1 is designed to be highly secure as a
  64-bit block cipher particularly to be provably
  secure against differential and linear
  cryptanalysis.

Powerful Cryptographic Attacks

• Differential Cryptanalysis (Biham, Shamir 1990)
• First DES attack faster than an exhaustive key
  search
• Linear Cryptanalysis (Matsui 1993)
• First successful computer experiment for breaking
  DES

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Multi Platform

• MISTY1 is designed to be sufficiently fast in
• both software and hardware implementations.
• Ex1) Pentium III (800MHz) (Assembly Language
  Program)
• Encryption speed
  230Mbps
• Ex2) ASIC H/W (Mitsubishi 0.35 micron CMOS
  Design Library)
• Encryption speed
  800Mbps
• Gate size
  50Kgates

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Compact

• Encryption/decryption logics of MISTY1
• can be realized in very compact size.
• Ex) ASIC (Mitsubishi 0.35 micron CMOS
  Design Library)
• Gate size
  7.6Kgates
• Encryption speed
  72Mbps
• Note
• A requirement for W-CDMA encryption
  algorithm gate size must be smaller than
  10Kgates

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Structure of MISTY
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Hardware
Memory
M16C(CPU)
MISTY1 core
M16C Core
RSA core
Rnd. Num. Gen.
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Current Status and Next Steps of MISTY1 to
support TLS

• Hirosato Tsuji
• Mitsubishi Electric Corporation
• lthirosato_at_iss.isl.melco.co.jpgt

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Summary

• What is MISTY1?
• High security, Multi platform, Compact, Block
  cipher
• In this presentation
• Actual Application of MISTY1
• Proposal of MISTY1
• Current Status to support TLS
• Next Steps to support TLS

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Actual Application of MISTY1 (1) Secure E-mail
Systems

• S/MIME-based e-mail application
• Extended S/MIME V2 specification
• Implemented by Mitsubishi and other Japanese
  venders
• Interoperability had been confirmed between
  these venders

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Actual Application of MISTY1 (2) Secure Web
Access Systems

• Secure Web Access Systems
• provide authentication, access control, integrity
  and confidentiality
• Implemented on the HTTP and TCP ( sorry, not on
  TLS )
• Contents is encrypted by MISTY1

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Actual Application of MISTY1 (3) Other Apps based
on MISTY Toolkit

• MISTY Cryptographic / PKI Toolkit
• Content Encryption Algorithm in PKCS 7
• Encryption Scheme ( Symmetric Cipher ) for PKCS
  5 Password-based Encryption
• Other Apps implemented on Toolkit
• Secure Contents Distribution Systems
• Governmental Services

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Proposal of MISTY1

• As ONE of block ciphers of Cipher Suites for
  TLS 1.0
• Reason to use MISTY1
• Suitable Block Cipher
• Royalty Free License
• Applied to Actual Internet Applications

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Current Status to support TLS

• Submit Internet Draft of Description of MISTY1
• posted.
• Make a presentation of MISTY1 at 48th IETF,
  Pittsburgh, PA
• now.

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Next Steps to support TLS

• Proceed Internet Draft of Description of MISTY1
  to Informational RFC
• Submit Internet Draft of MISTY1-based Cipher
  Suites for TLS 1.0
• Request TLS WG to assign the Register Number of
  these Cipher Suites

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Next Steps to support TLS (continued)

• Implementing TLS 1.0 with MISTY1
• processing now with OpenSSL