ISO/IEC INTERNATIONAL STANDARD 18033-5 Firstedition 2015-12-01 Information technology Security techniques Encryption algorithms Part 5: Identity-based ciphers Technologies de I'information - Techniques de sécurité - Algorithmes de chiffrement - Partie 5: Chiffrements identitaires Reference number IS0/IEC 18033-5:2015(E) IEC International Organization for Standardization STANDARDIZATION C1 5956617 @IS0/IEC2015 IS0/IEC 18033-5:2015(E) COPYRIGHTPROTECTEDDOCUMENT ISO/IEC2015,PublishedinSwitzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISOcopyrightoffice Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel.+41 22 749 01 11 Fax+412274909 47 copyright@iso.org www.iso.org Intenationai br PrganizationforStandardization icensee-ZHEJIANG INST.OF STANJSA6FEC 31.5 -All rights reserved I by IHS unde Not for Resale, 2016/3/29 05:38:20 etworking permitted without license from IHS IS0/IEC 18033-5:2015(E) Contents Page Foreword ..V Introduction. ...vi 1 Scope. 2 Normative references 3 Terms and definitions 4 Symbols, abbreviated terms and conversion functions 2 4.1 Symbols. .3 4.2 Abbreviated terms .3 4.3 Conversion functions .4 5 Cryptographic transforms .5 5.1 .5 General. 5.2 The function IHF1 .5 5.3 The function SHF1 .5 5.4 The function PHF1 . 6 6 General model for identity-based encryption .7 6.1 Composition of algorithms 6.2 Plaintext length .7 6.3 Use oflabels .8 6.4 Ciphertext format ..8 6.5 IBEoperation .8 7 General model for identity-based hybrid encryption .9 7.1 General .9 7.2 Identity-based key encapsulation .9 7.2.1 Composition of algorithms. ..9 7.2.2 Prefix-freeness. ..10 7.3 Data encapsulation... ..10 7.3.1 Composition of algorithms. ..10 7.4 Identity-based hybrid encryption operation .10 7.4.1 System parameters. ..10 7.4.2 Setup .11 7.4.3 Private key extraction. ..11 7.4.4 Encryption. .11 7.4.5 Decryption. .11 8 Identity-based encryption mechanism .11 8.1 General. .11 8.2 The BF mechanism .12 8.2.1 Set up. .12 8.2.2 Private key extraction. ..12 8.2.3 Encryption ..13 8.2.4 Decryption. ..14 Identity-based hybrid encryption mechanisms .14 9 9.1 General .14 9.2 The SK key encapsulation mechanism .14 9.2.1 Set up ..14 9.2.2 Private key extraction. .15 9.2.3 Session key encapsulation .16 9.2.4 Session key de-encapsulation. .16 9.3 The BB1 key encapsulation mechanism .17 9.3.1 Set up. ..17 9.3.2 Private key extraction. .. 17 9.3.3 Session key encapsulation. .18 iii nsee=ZHEJIANG INST OF STANDARDIZATION C1 5956617 ed without license from IHS Not for Resale, 2016/3/29 05:38:20