Proposal of MISTY1 as a Block Cipher of Cipher Suites in TLS Hirosato Tsuji Toshio Tokita Mitsubishi Electric Corporation

2000/08/0148th IETF, Pittsburgh, PA, USA2 Presentation Agenda  Current Status and Next Steps of MISTY1 to support TLS  Block Cipher “MISTY1” --- by Toshio Tokita --- by Hirosato Tsuji

Block Cipher Toshio Tokita Mitsubishi Electric Corporation MISTY1

2000/08/0148th IETF, Pittsburgh, PA, USA4 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 software, VPN(Routers/Hubs), Encryption LSI, PKI Software & services, etc, etc

2000/08/0148th IETF, Pittsburgh, PA, USA5 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. “KASUMI”=“MIST” 3GPP: 3rd Generation Partnership Project

2000/08/0148th IETF, Pittsburgh, PA, USA6 Pointers  ISO9979 No.13 (algorithm registration)  URL for Internet-Draft : misty1desc-02.txt  Specifications  Royalty Free License MISTY1 essential patent is licensed under royalty free conditions.

2000/08/0148th IETF, Pittsburgh, PA, USA7 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

2000/08/0148th IETF, Pittsburgh, PA, USA8 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. u Differential Cryptanalysis u Differential Cryptanalysis (Biham, Shamir 1990) – First DES attack faster than an exhaustive key search u Linear Cryptanalysis u Linear Cryptanalysis (Matsui 1993) – First successful computer experiment for breaking DES Powerful Cryptographic Attacks

2000/08/0148th IETF, Pittsburgh, PA, USA9 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

2000/08/0148th IETF, Pittsburgh, PA, USA10 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”

2000/08/0148th IETF, Pittsburgh, PA, USA11 Structure of MISTY

2000/08/0148th IETF, Pittsburgh, PA, USA12 Hardware M16C Core Memory Rnd. Num. Gen. RSA core MISTY1 core M16C(CPU)

Current Status and Next Steps of MISTY1 to support TLS Hirosato Tsuji Mitsubishi Electric Corporation

2000/08/0148th IETF, Pittsburgh, PA, USA14 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

2000/08/0148th IETF, Pittsburgh, PA, USA15 Actual Application of MISTY1 (1) Secure Systems  S/MIME-based application  Extended S/MIME V2 specification  Implemented by Mitsubishi and other Japanese venders  Interoperability had been confirmed between these venders

2000/08/0148th IETF, Pittsburgh, PA, USA16 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

2000/08/0148th IETF, Pittsburgh, PA, USA17 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

2000/08/0148th IETF, Pittsburgh, PA, USA18 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

2000/08/0148th IETF, Pittsburgh, PA, USA19 Current Status to support TLS  Submit Internet Draft of Description of MISTY1 – posted.  Make a presentation of MISTY1 at 48th IETF, Pittsburgh, PA – now.

2000/08/0148th IETF, Pittsburgh, PA, USA20 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

2000/08/0148th IETF, Pittsburgh, PA, USA21 Next Steps to support TLS (continued)  Implementing TLS 1.0 with MISTY1 – processing now with OpenSSL