SEED Overview ‘Use of the SEED Encryption Algorithm in CMS’ November 11, 2003 Jongwook Park, KISA

SEED Introduction Developed by KISA since 1998 Feistel structure with 16 rounds 128-bit input/output data block size 128-bit key length Robust against known attacks such as DC, LC and key related attacks Adopted to most of the security systems in Korea as a mandatory (e.g. cellular phone (WPKI), e-Government, Smartcard, Internet Banking…) Effectively implemented in software as well as hardware Licensing or royalty payments are not required

Overall Structure of the SEED B = A + B mod A i : Round DC G + D’C’ + G G + K i1 K i0 L 0 (64) R 0 (64) L 1 (64) R 1 (64) K 0 (64) K 1 (64) L 16 (64)R 16 (64) K 15 (64) L 2 (64) F F R 2 (64) F

SEED in CMS Content Encryption –Define id-seedCBC OID –Parameter field must have IV –Plain text padded before encrypt by number of appended octets Key Wrap –Define id-npki-app-cmsSeed-wrap OID –Identical to Section of RFC3394 (Key Wrap) with ‘AES’ replaced by ‘SEED’ –OID Parameter field must be NULL

Way Forward Publish the SEED algorithm itself as an informational RFC before Seoul meeting –Currently available SEED homepage (include source code and more…) Look for any comments from the list Watch for any ISO/IEC JTC1/SC 27 feedback and raise any significant issues to the WG