Reference / Paper · 2020
NIST SP 800-57 Part 1 Rev. 5 — Recommendation for Key Management: Part 1, General
NIST's key-length guidance, including RSA modulus sizes and their security strengths.
Reference / Paper · 2020
NIST's key-length guidance, including RSA modulus sizes and their security strengths.
NIST Special Publication 800-57 Part 1 Revision 5 Recommendation for Key Management: Part 1 – General Elaine Barker This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 C O M P U T E R S E C U R I T Y NIST Special Publication 800-57 Part 1 Revision 5 Recommendation for Key Management: Part 1 – General Elaine Barker Computer Security Division Information Technology Laboratory This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 May 2020 U.S. Department of Commerce Wilbur L. Ross, Jr., Secretary National Institute of Standards and Technology Walter Copan, NIST Director and Under Secretary of Commerce for Standards and Technology Authority This publication has been developed by the National Institute of Standards and Technology (NIST) in accordance with its statutory responsibilities under the Federal Information Security Modernization Act (FISMA) of 2014, 44 U.S.C. § 3551 et seq., Public Law (P.L.) 113-283. NIST is responsible for developing information security standards and guidelines, including minimum requirements for federal information systems, but such standards and guidelines shall not apply to national security systems without the express approval of appropriate federal officials exercising policy authority over such systems. This guideline is consistent with the requirements of the Office of Management and Budget (OMB) Circular A-130. Nothing in this publication should be taken to contradict the standards and guidelines made mandatory and binding on federal agencies by the Secretary of Commerce under statutory authority. Nor should these guidelines be interpreted as altering or superseding the existing authorities of the Secretary of Commerce, Director of the OMB, or any other federal official. This publication may be used by nongovernmental organizations on a voluntary basis and is not subject to copyright in the United States. Attribution would, however, be appreciated by NIST. National Institute of Standards and Technology Special Publication 800-57 Part 1, Revision 5 Natl. Inst. Stand. Technol. Spec. Publ. 800-57 Part 1 Rev. 5, 170 pages (May 2020) CODEN: NSPUE2 This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 Certain commercial entities, equipment, or materials may be identified in this document in order to describe an experimental procedure or concept adequately. Such identification is not intended to imply recommendation or endorsement by NIST, nor is it intended to imply that the entities, materials, or equipment are necessarily the best available for the purpose. There may be references in this publication to other publications currently under development by NIST in accordance with its assigned statutory responsibilities. The information in this publication, including concepts and methodologies, may be used by federal agencies even before the completion of such companion publications. Thus, until each publication is completed, current requirements, guidelines, and procedures, where they exist, remain operative. For planning and transition purposes, federal agencies may wish to closely follow the development of these new publications by NIST. Organizations are encouraged to review all draft publications during public comment periods and provide feedback to NIST. Many NIST cybersecurity publications, other than the ones noted above, are available at https://csrc.nist.gov/publications. Comments on this publication may be submitted to: National Institute of Standards and Technology Attn: Computer Security Division, Information Technology Laboratory 100 Bureau Drive (Mail Stop 8930) Gaithersburg, MD 20899-8930 Email: [email protected] All comments are subject to release under the Freedom of Information Act (FOIA). NIST SP 800-57 PART 1 REV. 5 RECOMMENDATION FOR KEY MANAGEMENT: PART 1 – GENERAL Reports on Computer Systems Technology This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 The Information Technology Laboratory (ITL) at the National Institute of Standards and Technology (NIST) promotes the U.S. economy and public welfare by providing technical leadership for the Nation’s measurement and standards infrastructure. ITL develops tests, test methods, reference data, proof of concept implementations, and technical analyses to advance the development and productive use of information technology. ITL’s responsibilities include the development of management, administrative, technical, and physical standards and guidelines for the cost-effective security and privacy of other than national securityrelated information in Federal information systems. The Special Publication 800-series reports on ITL’s research, guidelines, and outreach efforts in information system security, and its collaborative activities with industry, government, and academic organizations. Abstract This Recommendation provides cryptographic key-management guidance. It consists of three parts. Part 1 provides general guidance and best practices for the management of cryptographic keying material, including definitions of the security services that may be provided when using cryptography and the algorithms and key types that may be employed, specifications of the protection that each type of key and other cryptographic information requires and methods for providing this protection, discussions about the functions involved in key management, and discussions about a variety of key-management issues to be addressed when using cryptography. Part 2 provides guidance on policy and security planning requirements for U.S. government agencies. Part 3 provides guidance when using the cryptographic features of current systems. Keywords archive; authentication; authorization; availability; backup; compromise; confidentiality; cryptographic key; cryptographic module; digital signature; hash function; key agreement; key management; key recovery; keying material; key transport; private key; public key; secret key; trust anchor. ii NIST SP 800-57 PART 1 REV. 5 RECOMMENDATION FOR KEY MANAGEMENT: PART 1 – GENERAL Acknowledgments The National Institute of Standards and Technology (NIST) gratefully acknowledges and appreciates contributions by previous authors of this document on the many security issues associated with this Recommendation: William Barker, William Burr, and Timothy Polk from NIST; Miles Smid from Orion Security; and Lydia Zieglar from the National Security Agency. NIST also thanks the many contributions by the public and private sectors whose thoughtful and constructive comments improved the quality and usefulness of this publication. NIST especially appreciates the comments submitted before, during, and after the public comment period by Paul Turner from Venafi. This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 Patent Disclosure Notice NOTICE: The Information Technology Laboratory (ITL) has requested that holders of patent claims whose use may be required for compliance with the guidance or requirements of this publication disclose such patent claims to ITL. However, holders of patents are not obligated to respond to ITL calls for patents and ITL has not undertaken a patent search in order to identify which, if any, patents may apply to this publication. As of the date of publication and following call(s) for the identification of patent claims whose use may be required for compliance with the guidance or requirements of this publication, no such patent claims have been identified to ITL. No representation is made or implied by ITL that licenses are not required to avoid patent infringement in the use of this publication. iii NIST SP 800-57 PART 1 REV. 5 RECOMMENDATION FOR KEY MANAGEMENT: PART 1 – GENERAL Executive Summary Cryptography is used to secure communications over networks, to protect information stored in databases, and for many other critical applications. Cryptographic keys play an important part in the operation of cryptography. These keys are analogous to the combination of a safe. If a safe combination is known to an adversary, the strongest safe provides no security against penetration. This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 The proper management of cryptographic keys is essential to the effective use of cryptography for security. Poor key management may easily compromise strong algorithms. This Recommendation provides guidance on the management of a cryptographic key throughout its lifecycle, including its secure generation, storage, distribution, use, and destruction. Ultimately, the security of information protected by cryptography directly depends on the strength of the keys, the effectiveness of cryptographic mechanisms and protocols associated with the keys, and the protection provided to the keys. Secret and private keys need to be protected against unauthorized disclosure, and all keys need to be protected against modification. Cryptographic keys are used across a broad range of systems and applications in enterprises, many of which are managed by individuals who may not have expertise in key management. Consequently, organizations must ensure that clear guidance and oversight is provided for the proper management of keys, as well as controls to ensure that the guidance is being properly followed and implemented. Organizations and developers are presented with many choices in their use of cryptographic mechanisms. Inappropriate choices may result in an illusion of security but little or no real security for the protocol or application. This Recommendation (i.e., Special Publication (SP) 800-57) provides background information and establishes frameworks to support appropriate decisions when selecting and using cryptographic mechanisms. Cryptographic modules are used to perform cryptographic operations using these keys. This Recommendation does not address the implementation details for cryptographic modules that may be used to achieve the security requirements identified herein. These details are addressed in Federal Information Processing Standard (FIPS) 140 [FIPS 140] and its associated implementation guidance and derived test requirements (available at https://csrc.nist.gov/projects/cmvp/). This Recommendation is written for several different audiences and is divided into three parts: • Part 1, General, contains basic key-management guidance. It is intended to advise developers and system administrators on the “best practices” associated with key management. Cryptographic module developers may benefit from this general guidance by obtaining a greater understanding of the key-management features that are required to support specific applications. Protocol developers may identify key-management characteristics associated with specific suites of algorithms and gain a greater understanding of the security services provided by those algorithms. System administrators may use this document to assist in determining which configuration settings are most appropriate for their information. Part 1 of the Recommendation: 1. Defines the security services that may be provided and the key types that may be employed in using cryptographic mechanisms; 2. Provides background information regarding the cryptographic algorithms that use cryptographic keying material; iv NIST SP 800-57 PART 1 REV. 5 RECOMMENDATION FOR KEY MANAGEMENT: PART 1 – GENERAL 3. Classifies the different types of keys and other cryptographic information according to their functions, specifies the protection that each type of information requires, and identifies methods for providing this protection; 4. Identifies the states in which a cryptographic key may exist during its lifetime; 5. Identifies the multitude of functions involved in key management; and This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 6. Discusses a variety of key-management issues related to the keying material; topics discussed include key usage, cryptoperiod length, domain-parameter validation, public-key validation, key-inventory management, accountability, audit, survivability, and guidance for cryptographic algorithm and key size selection. • Part 2, Best Practices for Key Management Organizations, is primarily intended to address the needs of system owners and managers. It provides a framework and general guidance to support establishing cryptographic key management within an organization and a basis for satisfying the key-management aspects of statutory and policy security planning requirements for federal government organizations. • Part 3, Application-Specific Key Management Guidance, is intended to address the keymanagement issues associated with currently available implementations that use cryptography. v NIST SP 800-57 PART 1 REV. 5 RECOMMENDATION FOR KEY MANAGEMENT: PART 1 – GENERAL Table of Contents Executive Summary ..................................................................................................... iv 1 Introduction ............................................................................................................... 1 1.1 1.2 1.3 1.4 1.5 Purpose ..............................................................................................................................1 Audience ............................................................................................................................1 Scope .................................................................................................................................2 Purpose of FIPS and NIST Recommendations (NIST Standards) ....................................3 Content and Organization ..................................................................................................4 This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 2 Glossary of Terms and Acronyms ........................................................................... 6 2.1 2.2 Glossary .............................................................................................................................6 Acronyms ........................................................................................................................20 3 Security Services .................................................................................................... 22 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Confidentiality .................................................................................................................22 Data Integrity ...................................................................................................................22 Authentication .................................................................................................................22 Authorization ...................................................................................................................23 Non-repudiation ...............................................................................................................23 Support Services ..............................................................................................................23 Combining Services.........................................................................................................23 4 Cryptographic Algorithms ...................................................................................... 27 4.1 4.2 4.3 4.4 Cryptographic Hash Functions ........................................................................................27 Symmetric-Key Algorithms ............................................................................................28 Asymmetric-Key Algorithms ..........................................................................................29 Random Bit Generation ...................................................................................................29 5 General Key-Management Guidance ..................................................................... 30 5. 1 Key Types and Other Information ...................................................................................30 5.1.1 5.1.2 5.2 5.3 Cryptographic Keys ............................................................................................30 Other Related Information ..................................................................................32 Key Usage .......................................................................................................................33 Cryptoperiods ..................................................................................................................34 5.3.1 5.3.2 5.3.3 Factors Affecting Cryptoperiods.........................................................................34 Consequence Factors Affecting Cryptoperiods ..................................................35 Other Factors Affecting Cryptoperiods ..............................................................36 5.3.3.1 5.3.3.2 5.3.4 5.3.5 5.3.6 5.3.7 Communications versus Storage ........................................................36 Cost of Key Revocation and Replacement .........................................36 Asymmetric Key Usage Periods and Cryptoperiods ..........................................36 Symmetric Key Usage Periods and Cryptoperiods .............................................37 Cryptoperiod Recommendations for Specific Key Types ..................................38 Recommendations for Other Related Information..............................................47 vi NIST SP 800-57 PART 1 REV. 5 5.4 Assurances .......................................................................................................................47 5.4.1 5.4.2 5.4.3 5.4.4 5.4.5 5.5 Assurance of Integrity (Integrity Protection) ......................................................47 Assurance of Domain Parameter Validity ..........................................................47 Assurance of Public-Key Validity ......................................................................48 Assurance of Private-Key Possession .................................................................48 Key Confirmation ...............................................................................................48 Compromise of Keys and other Keying Material............................................................49 This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 5.5.1 5.5.2 5.6 RECOMMENDATION FOR KEY MANAGEMENT: PART 1 – GENERAL Implications.........................................................................................................49 Protective Measures ............................................................................................50 Guidance for Cryptographic Algorithm and Key-Size Selection ....................................52 5.6.1 Comparable Algorithm Strengths .......................................................................52 5.6.1.1 5.6.1.2 5.6.2 5.6.3 5.6.4 5.6.5 Security Strengths of Symmetric Block Cipher and Asymmetric-Key Algorithms ..........................................................................................53 Security Strengths of Hash Functions and Hash-based Functions .....55 Using Algorithm Suites and the Effective Security Strength .............................57 Projected Security Strength Time Frames and Current Approval Status ...........59 Transitioning to New Algorithms and Key Sizes in Systems .............................60 Decrease of Security Strength Over Time ..........................................................62 6 Protection Requirements for Key Information ...................................................... 65 6.1 Protection and Assurance Requirements .........................................................................65 6.1.1 6.1.2 6.2 Summary of Protection and Assurance Requirements for Cryptographic Keys.66 Summary of Protection Requirements for Other Related Information ...............70 Protection Mechanisms ...................................................................................................72 6.2.1 Protection Mechanisms for Key Information in Transit .....................................72 6.2.1.1 6.2.1.2 6.2.1.3 6.2.1.4 6.2.1.5 6.2.1.6 6.2.2 Protection Mechanisms for Key Information in Storage ....................................75 6.2.2.1 6.2.2.2 6.2.2.3 6.2.2.4 6.2.2.5 6.2.2.6 6.2.3 Availability .........................................................................................73 Integrity ..............................................................................................73 Confidentiality ....................................................................................74 Association with Usage or Application ..............................................75 Association with Other Entities ..........................................................75 Association with Other Related Key Information ..............................75 Availability .........................................................................................75 Integrity ..............................................................................................76 Confidentiality ...................................................................................77 Association with Usage or Application ..............................................77 Association with the Other Entities ....................................................77 Association with Other Related Key Information ..............................77 Metadata for Keys ...............................................................................................78 7 Key States and Transitions .................................................................................... 80 vii NIST SP 800-57 PART 1 REV. 5 7.1 7.2 7.3 7.4 7.5 7.6 RECOMMENDATION FOR KEY MANAGEMENT: PART 1 – GENERAL Pre-activation State ..........................................................................................................81 Active State .....................................................................................................................82 Suspended State ...............................................................................................................84 Deactivated State .............................................................................................................86 Compromised State .........................................................................................................87 Destroyed State ................................................................................................................88 8 Key-Management Phases and Functions.............................................................. 89 8.1 Pre-operational Phase ......................................................................................................90 This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 8.1.1 8.1.2 8.1.3 8.1.4 8.1.5 Entity Registration Function ...............................................................................90 System Initialization Function ............................................................................92 Initialization Function .........................................................................................92 Keying-Material Installation Function................................................................92 Key Establishment Function ...............................................................................92 8.1.5.1 Generation and Distribution of Asymmetric Key Pairs .....................93 8.1.5.1.1 Distribution of Public Keys ................................................................. 93 8.1.5.1.2 Distribution of Ephemeral Public Keys ............................................... 98 8.1.5.1.3 Distribution of Centrally Generated Key Pairs.................................... 98 8.1.5.2 Generation and Distribution of Symmetric Keys ...............................99 8.1.5.2.1 Key Generation .................................................................................... 99 8.1.5.2.2 Key Distribution .................................................................................. 99 8.1.5.2.3 Key Agreement .................................................................................. 101 8.1.5.3 Generation and Distribution of Other Keying Material ...................102 8.1.5.3.1 Domain Parameters ........................................................................... 102 8.1.5.3.2 Initialization Vectors ......................................................................... 102 8.1.5.3.3 Shared Secrets ................................................................................... 102 8.1.5.3.4 RBG Seeds......................................................................................... 102 8.1.5.3.5 Other Public and Secret Information ................................................. 102 8.1.5.3.6 Intermediate Results .......................................................................... 103 8.1.5.3.7 Random Bits/Numbers ...................................................................... 103 8.1.5.3.8 Passwords .......................................................................................... 103 8.1.6 8.2 Key Registration Function ................................................................................103 Operational Phase ..........................................................................................................104 8.2.1 Normal Operational Storage Function ..............................................................104 8.2.1.1 8.2.1.2 8.2.2 Continuity of Operations Function ...................................................................104 8.2.2.1 8.2.2.2 8.2.3 Cryptographic Module Storage ........................................................104 Immediately Accessible Storage Media ...........................................104 Backup Storage.................................................................................105 Key Recovery Function ....................................................................107 Key Change Function .......................................................................................107 8.2.3.1 Re-keying .........................................................................................108 viii NIST SP 800-57 PART 1 REV. 5 8.2.3.2 8.2.4 8.3 Key Update Function........................................................................108 Key Derivation Methods ...................................................................................108 Post-Operational Phase ..................................................................................................109 8.3.1 8.3.2 8.3.3 8.3.4 8.3.5 This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 8.4 RECOMMENDATION FOR KEY MANAGEMENT: PART 1 – GENERAL Key Archive and Key Recovery Functions ......................................................109 Entity De-registration Function ........................................................................112 Key De-registration Function ...........................................................................113 Key Destruction Function .................................................................................113 Key Revocation Function .................................................................................113 Destroyed Phase ............................................................................................................115 9 Additional Considerations.................................................................................... 116 9.1 9.2 Access Control and Identity Authentication..................................................................116 Inventory Management ..................................................................................................116 9.2.1 9.2.2 9.3 9.4 9.5 Key Inventories .................................................................................................117 Certificate Inventories.......................................................................................117 Accountability ...............................................................................................................118 Audit ..............................................................................................................................119 Key-Management System Survivability........................................................................120 9.5.1 9.5.2 9.5.3 Backed Up and Archived Key ..........................................................................120 Key Recovery....................................................................................................120 System Redundancy/Contingency Planning .....................................................122 9.5.3.1 9.5.3.2 9.5.4 General Principles ............................................................................123 Cryptography and Key-Management-Specific Recovery Issues......124 Compromise Recovery......................................................................................124 References ................................................................................................................. 126 Appendix A—Cryptographic and Non-cryptographic Integrity and Source Authentication Mechanisms ........................................................................ 132 Appendix B—Key Recovery ..................................................................................... 135 B.1 Recovery from Stored Keying Material ........................................................................136 B.2 Recovery by Reconstruction of Keying Material ..........................................................136 B.3 Conditions Under Which Keying Material Needs to be Recoverable ...........................136 B.3.1 Signature Key Pairs...........................................................................................136 B.3.1.1 B.3.1.2 B.3.2 B.3.3 Symmetric Authentication Keys .......................................................................137 Authentication Key Pairs ..................................................................................138 B.3.3.1 B.3.3.2 B.3.4 Private Signature Keys .....................................................................136 Public Signature-verification Keys ..................................................137 Public Authentication Keys ..............................................................138 Private Authentication Keys .............................................................138 Symmetric Data-Encryption Keys ....................................................................139 ix NIST SP 800-57 PART 1 REV. 5 B.3.5 B.3.6 B.3.7 B.3.8 RECOMMENDATION FOR KEY MANAGEMENT: PART 1 – GENERAL Symmetric Key-Wrapping Keys .......................................................................139 Random Number Generation Keys ...................................................................139 Symmetric Master/Key-Derivation Keys .........................................................139 Key-Transport Key Pairs ..................................................................................140 B.3.8.1 B.3.8.2 Private Key-Transport Keys .............................................................140 Public Key-Transport Keys ..............................................................140 B.3.9 Symmetric Key-Agreement Keys .....................................................................141 B.3.10 Static Key-Agreement Key Pairs ......................................................................141 This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 B.3.10.1 Private Static Key-Agreement Keys.................................................141 B.3.10.2 Public Static Key Agreement Keys ..................................................141 B.3.11 Ephemeral Key Pairs.........................................................................................141 B.3.11.1 Private Ephemeral Keys ...................................................................142 B.3.11.2 Public Ephemeral Keys ....................................................................142 B.3.12 Symmetric Authorization Keys.........................................................................142 B.3.13 Authorization Key Pairs....................................................................................142 B.3.13.1 Private Authorization Keys ..............................................................142 B.3.13.2 Public Authorization Keys ...............................................................142 B.3.14 Other Related Information ................................................................................142 B.3.14.1 Domain Parameters ..........................................................................142 B.3.14.2 Initialization Vectors (IVs) ...............................................................143 B.3.14.3 Shared Secrets ..................................................................................143 B.3.14.4 RBG Seeds .......................................................................................143 B.3.14.5 Other Public and Secret Information ................................................143 B.3.14.6 Intermediate Results .........................................................................143 B.3.14.7 Key-Control Information/Metadata ..................................................143 B.3.14.8 Random Numbers .............................................................................144 B.3.14.9 Passwords .........................................................................................144 B.3.14.10 Audit Information .............................................................................144 B.4 Key Recovery Systems ..................................................................................................144 B.5 Key Recovery Policy .....................................................................................................145 Appendix C—Revision History ................................................................................ 147 List of Tables Table 1: Suggested cryptoperiods for key types ............................................................................45 Table 2: Comparable security strengths of symmetric block cipher and asymmetric-key algorithms.......................................................................................................................54 Table 3: Maximum security strengths for hash and hash-based functions ....................................56 Table 4: Security strength time frames ..........................................................................................59 x NIST SP 800-57 PART 1 REV. 5 RECOMMENDATION FOR KEY MANAGEMENT: PART 1 – GENERAL Table 5: Protection requirements for cryptographic keys ..............................................................67 Table 6: Protection requirements for other related information ....................................................71 Table 7: Backup of keys ..............................................................................................................105 Table 8: Backup of other related information ..............................................................................106 Table 9: Archive of keys ..............................................................................................................110 Table 10: Archive of other related information ...........................................................................111 This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 List of Figures Figure 1: Symmetric-key cryptoperiod ..........................................................................................38 Figure 2: Algorithm originator-usage period example ..................................................................60 Figure 3: Key state and transition example....................................................................................80 Figure 4: Key-management phases ................................................................................................89 Figure 5: Key-management states and phases ...............................................................................91 xi NIST SP 800-57 PART 1 REV. 5 RECOMMENDATION FOR KEY MANAGEMENT: PART 1 – GENERAL 1 Introduction The use of cryptographic mechanisms is one of the strongest ways to provide security services for communications, data storage, and other applications. The National Institute of Standards and Technology (NIST) publishes Federal Information Processing Standards (FIPS) and NIST Recommendations (which are published as Special Publications (SPs)) that specify cryptographic techniques for protecting sensitive, unclassified information. This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.800-57pt1r5 Since NIST published the Data Encryption Standard (DES) in 1977, the suite of approved standardized algorithms has grown. New classes of algorithms have been added, such as secure hash functions and asymmetric key algorithms for digital signatures. The suite of algorithms now provides different levels of cryptographic strength through a variety of key lengths. The algorithms may be combined in many ways to support increasingly complex protocols and applications. This NIST Recommendation applies to U.S. government agencies using cryptography for the protection of their sensitive, unclassified information. On a voluntary basis, this Recommendation may also be followed by other organizations that want to implement sound security principles in their computer systems. The proper management of cryptographic keys and other key information is essential to the effective use of cryptography for security. Keys are analogous to the combination of a safe. If an adversary knows the combination, the strongest safe provides no security against penetration. Similarly, poor key management may easily compromise strong algorithms. Ultimately, the security of the information protected by cryptography directly depends on the strength of the keys, the effectiveness of the mechanisms and protocols associated with the keys, and the protection afforded to the keys. Cryptography can be rendered ineffective by the use of weak implementations, inappropriate algorithm pairing, poor physical security, and the use of weak (i.e., vulnerable) protocols. Key management is the process of managing a key throughout its lifecycle, including its secure generation, storage, distribution, use, and destruction. Keys may be managed manually, but in many cases, an automated system is required to oversee, automate, and secure the keymanagement process. An automated system that performs key management is commonly known as a (cryptographic) key management system; see SP 800-130 1 and SP 800-152. 2 1.1 Purpose Organizations and developers are presented with many new choices in their use of cryptographic mechanisms. Inappropriate choices may result in an illusion of security but little or no real security for the protocol or application. This Recommendation (i.e., SP 800-57) provides background information and establishes frameworks to support appropriate decisions when select