Standard No.:	GB/T 17964-2008
English Name:	Information technology - Security techniques - Modes of operation for a block cipher
Chinese Name:	信息安全技术 分组密码算法的工作模式
Chinese Classification:	L80    Data encryption
Professional Classification:	GB    National Standard
Source Content Issued by:	AQSIQ SAC
Issued on:	2008-6-26
Implemented on:	2008-11-1
Status:	superseded
Superseded by:	GB/T 17964-2021
Superseded on:	2022-5-1
Superseding:	GB/T 17964-2000 Information technology--Security techniques--Modes of operation for an n-bit block cipher
Target Language:	English
File Format:	PDF
Word Count:	12500 words
Translation Price(USD):	140.0
Delivery:	via email in 1 business day

1 Scope This standard establishes seven operation modes for block cipher to standardize the application of block cipher. 2 Normative References The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding any corrigendum), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For any undated references, the latest edition of the document referred to applies. GB/T 1988-1998 Information Technology—7-bit Coded Character Set for Information Interchange (eqv ISO/IEC 646:1991) 3 Terms and Definitions For the purposes of this standard, the following terms and definitions apply. 3.1 Terms 3.1.1 block chaining (BC) operation mode one operation mode for block cipher, which is applied to obtain the current ciphertext block by encryption after XOR operation on the current plaintext block with the XOR values of all preceding ciphertext blocks 3.1.2 block cipher also called block cipher algorithm, a kind of symmetric encryption algorithm which encrypts the plaintext divided into blocks of fixed length 3.1.3 block cipher operation mode block cipher operation mode mainly includes electronic codebook (ECB), cipher block chaining (CBC), cipher feedback (CFB), output feedback (OFB) and counter (CTR) operation modes

Foreword i Introduction ii 1 Scope 2 Normative References 3 Terms and Definitions 3.1 Terms 3.2 Definitions 4 Abbreviations and Symbols 5 Electronic Codebook (ECB) Mode 5.1 Variable Definition 5.2 ECB Mode of Encryption 5.3 ECB Mode of Decryption 6 Cipher Block Chaining (CBC) Mode 6.1 Variable Definition 6.2 CBC Mode of Encryption 6.3 CBC Mode of Decryption 7 Cipher Feedback (CFB) Mode 7.1 Parameter Definition 7.2 Variable Definition 7.3 CFB Mode of Encryption 7.4 CFB Mode of Decryption 7.5 Suggestion 8 Output Feedback (OFB) Mode 8.1 Parameter Definition 8.2 Variable Definition 8.3 OFB Mode of Encryption 8.4 OFB Mode of Decryption 9 Counter (CTR) Mode 9.1 Variable Definition 9.2 CTR Mode of Encryption 9.3 CTR Mode of Decryption 10 Block Chaining (BC) Mode 10.1 Variable Definition 10.2 BC Mode of Encryption 10.3 BC Mode of Decryption 11 Output Feedback with a Nonlinear Function (OFBNLF) Operation Mode 11.1 Variable Definition 11.2 OFBNLF Mode of Encryption 11.3 OFBNLF Mode of Decryption Annex A (Normative) Properties of Operation Modes A.1 Properties of the Electronic Codebook (ECB) Operation Mode A.2 Properties of the Cipher Block Chaining (CBC) Operation Mode A.3 Properties of the Cipher Feedback (CFB) Operation Mode A.4 Properties of the Output Feedback (OFB) Operation Mode A.5 Properties of Counter (CTR) Operation Modes A.6 Properties of the Block Chaining (BC) Operation Mode A.7 Properties of the Output Feedback with a Nonlinear Function (OFBNLF) Operation Mode Annex B (Informative) Examples for the Operation Modes B.1 General B.2 ECB Mode B.3 CBC Mode B.4 CFB Mode B.5 OFB Mode B.6 CTR Mode Bibliography