IEEE P1619
Encyclopedia
IEEE P1619 is an Institute of Electrical and Electronics Engineers
(IEEE) standardization project for encryption of stored data, but more generically refers to the work of the IEEE P1619 Security in Storage Working Group (SISWG), which includes a family of standards for protection of stored data and for the corresponding cryptographic key management.
P1619 has also standardized the key backup in the XML
format.
. Narrow-block algorithms have the advantage of more efficient hardware implementation. On the other hand, smaller block size provides finer granularity for data modification attacks. There is no standardized "acceptable granularity"; however, for example, the possibility of data modification with the granularity of one bit (bit-flipping attack
) is generally considered unacceptable.
For these reasons, the working group has selected the narrow-block (128 bits) encryption with no authentication in the standard P1619, assuming that the added efficiency warrants the additional risk. But recognizing that wide-block encryption might be useful in some cases, another project P1619.2 has been started to study the usage of wide-block encryption.
A discussion is ongoing on standardization of the wide-block encryption for disk drives, like CMC and EME as P1619.2, and on key management as P1619.3.
in LRW mode. In the Aug 30, 2006 meeting of the SISWG, a straw poll showed that most members would not approve P1619 "as is". Consequently, LRW-AES has been replaced by the XEX-AES tweakable block cipher in P1619.0 Draft 7 (and renamed to XTS-AES in Draft 11). Some members of the group found it non-trivial to abandon LRW, because it had been available for public peer-review for many years (unlike most of the newly suggested variants). The issues of LRW were:
Institute of Electrical and Electronics Engineers
The Institute of Electrical and Electronics Engineers is a non-profit professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence...
(IEEE) standardization project for encryption of stored data, but more generically refers to the work of the IEEE P1619 Security in Storage Working Group (SISWG), which includes a family of standards for protection of stored data and for the corresponding cryptographic key management.
SISWG Standards Overview
SISWG oversees work on the following standards:- P1619 Standard Architecture for Encrypted Shared Storage Media
- Uses the XTS-AESAdvanced Encryption StandardAdvanced Encryption Standard is a specification for the encryption of electronic data. It has been adopted by the U.S. government and is now used worldwide. It supersedes DES...
(XEX-based Tweaked CodeBook mode (TCB) with CipherText StealingCiphertext stealingIn cryptography, ciphertext stealing is a general method of using a block cipher mode of operation that allows for processing of messages that are not evenly divisible into blocks without resulting in any expansion of the ciphertext, at the cost of slightly increased complexity.-General...
(CTS); the proper name should be XTC (XEX TCB CTS), but that is already used to denote the ecstasy drug).
- Uses the XTS-AES
P1619.1
- P1619.1 Standard for Authenticated Encryption with Length Expansion for Storage Devices
- Uses the following algorithms
- Counter mode with CBC-MACCCM modeCCM mode is a mode of operation for cryptographic block ciphers. It is an authenticated encryption algorithm designed to provide both authentication and confidentiality. CCM mode is only defined for block ciphers with a block length of 128 bits...
(CCM) - Galois/Counter ModeGalois/Counter ModeGalois/Counter Mode is a mode of operation for symmetric key cryptographic block ciphers that has been widely adopted because of its efficiency and performance...
(GCM) - CBC-HMACHMACIn cryptography, HMAC is a specific construction for calculating a message authentication code involving a cryptographic hash function in combination with a secret key. As with any MAC, it may be used to simultaneously verify both the data integrity and the authenticity of a message...
-SHAShaFor other uses, see Sha .Sha is a letter of the Cyrillic alphabet. It commonly represents the voiceless postalveolar fricative , like the pronunciation of ⟨sh⟩ in "sheep", or the somewhat similar voiceless retroflex fricative . It is used in every variation of the Cyrillic alphabet, for Slavic and... - XTS-HMACHMACIn cryptography, HMAC is a specific construction for calculating a message authentication code involving a cryptographic hash function in combination with a secret key. As with any MAC, it may be used to simultaneously verify both the data integrity and the authenticity of a message...
-SHAShaFor other uses, see Sha .Sha is a letter of the Cyrillic alphabet. It commonly represents the voiceless postalveolar fricative , like the pronunciation of ⟨sh⟩ in "sheep", or the somewhat similar voiceless retroflex fricative . It is used in every variation of the Cyrillic alphabet, for Slavic and...
- Counter mode with CBC-MAC
- Uses the following algorithms
P1619.2
- P1619.2 Standard for Wide-Block Encryption for Shared Storage Media
- Proposed algorithms include:
- XCB http://eprint.iacr.org/2004/278.pdf
- EME2
- Proposed algorithms include:
P1619.3
- P1619.3 Standard for Key Management Infrastructure for Cryptographic Protection of Stored Data
- Defines a system for managing encryption data at rest security objects which includes:
- Architecture
- Namespaces
- Operations
- Messaging
- Transport
- Defines a system for managing encryption data at rest security objects which includes:
P1619 has also standardized the key backup in the XML
XML
Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
format.
Narrow-block vs. wide-block encryption
An encryption algorithm used for data storage has to support independent encryption and decryption of portions of data. So called narrow-block algorithms operate on relatively small portions of data, while the wide-block algorithms encrypt or decrypt a whole sectorCylinder-head-sector
Cylinder-head-sector, also known as CHS, was an early method for giving addresses to each physical block of data on a hard disk drive. In the case of floppy drives, for which the same exact diskette medium can be truly low-level formatted to different capacities, this is still true.Though CHS...
. Narrow-block algorithms have the advantage of more efficient hardware implementation. On the other hand, smaller block size provides finer granularity for data modification attacks. There is no standardized "acceptable granularity"; however, for example, the possibility of data modification with the granularity of one bit (bit-flipping attack
Bit-flipping attack
A bit-flipping attack is an attack on a cryptographic cipher in which the attacker can change the ciphertext in such a way as to result in a predictable change of the plaintext, although the attacker is not able to learn the plaintext itself...
) is generally considered unacceptable.
For these reasons, the working group has selected the narrow-block (128 bits) encryption with no authentication in the standard P1619, assuming that the added efficiency warrants the additional risk. But recognizing that wide-block encryption might be useful in some cases, another project P1619.2 has been started to study the usage of wide-block encryption.
Current status
The project is maintained by the IEEE Security in Storage Working Group (SISWG) https://siswg.net. Both the disk storage standard P1619 (a.k.a. P1619.0) and the tape storage standard P1619.1 were standardized in 2007-12-19.A discussion is ongoing on standardization of the wide-block encryption for disk drives, like CMC and EME as P1619.2, and on key management as P1619.3.
LRW issue
From the year 2004 to the year 2006, drafts of the P1619 standards were using AESAdvanced Encryption Standard
Advanced Encryption Standard is a specification for the encryption of electronic data. It has been adopted by the U.S. government and is now used worldwide. It supersedes DES...
in LRW mode. In the Aug 30, 2006 meeting of the SISWG, a straw poll showed that most members would not approve P1619 "as is". Consequently, LRW-AES has been replaced by the XEX-AES tweakable block cipher in P1619.0 Draft 7 (and renamed to XTS-AES in Draft 11). Some members of the group found it non-trivial to abandon LRW, because it had been available for public peer-review for many years (unlike most of the newly suggested variants). The issues of LRW were:
- An attacker can derive the LRW tweak key K2 from the ciphertext if the plaintext contains K2||0n or 0n||K2. Here || is the concatenation operator and 0n is a zero block. This may be an issue for software that encrypts the partition of an operating system under which this encryption software is running (at the same time). The operating system could write the LRW tweak key to encrypted swap/hibernation file.
- If the tweak key K2 is known, LRW does not offer indistinguishability under chosen plaintext attack (IND-CPA) anymore, and the same input block permutation attacks of ECB mode are possible. Leak of the tweak key does not have an impact on the confidentiality of the plaintext.
See also
- Comparison of disk encryption softwareComparison of disk encryption software-Background information:-Operating systems:-Features:* Hidden containers: Whether hidden containers can be created for deniable encryption...
- Disk encryptionDisk encryptionDisk encryption is a special case of data at rest protection when the storage media is a sector-addressable device . This article presents cryptographic aspects of the problem...
- EncryptionEncryptionIn cryptography, encryption is the process of transforming information using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information...
- Full disk encryptionFull disk encryptionDisk encryption uses disk encryption software or hardware to encrypt every bit of data that goes on a disk or disk volume. Disk encryption prevents unauthorized access to data storage. The term "full disk encryption" is often used to signify that everything on a disk is encrypted, including the...
- Key managementKey managementKey management is the provisions made in a cryptography system design that are related to generation, exchange, storage, safeguarding, use, vetting, and replacement of keys. It includes cryptographic protocol design, key servers, user procedures, and other relevant protocols.Key management concerns...
- KMIPKMIPThe Key Management Interoperability Protocol tries to establish a single, comprehensive protocol for the communication between enterprise key management systems and encryption systems. By using a consolidated protocol, organizations will be able to simplify key management and reduce operational...
- OTFEOTFEOn-the-fly encryption , also known as Real-time Encryption, is a method used by some encryption programs, for example, disk encryption software...
External links
- SISWG home page
- Email archive for SISWG in general and P1619 in particular
- Email archive for P1619.1 (Authenticated Encryption)
- Email archive for P1619.2 (Wide-block Encryption)
- Email archive for P1619.3 (Key Management)