ISO/TC 68/SC 2/WG 13 - Security in retail banking

This document specifies the security framework for using biometrics for authentication of customers in financial services, focusing exclusively on retail payments. It introduces the most common types of biometric technologies and addresses issues concerning their application. This document also describes representative architectures for the implementation of biometric authentication and associated minimum control objectives. The following are within the scope of this document: — use of biometrics for the purpose of: — verification of a claimed identity; — identification of an individual; — biometric authentication threats, vulnerabilities and controls; — validation of credentials presented at enrolment to support authentication; — management of biometric information across its life cycle, comprising enrolment, transmission and storage, verification, identification and termination processes; — security requirements for hardware used in conjunction with biometric capture and biometric data processing; — biometric authentication architectures and associated security requirements. The following are not within the scope of this document: — detailed specifications for data collection, feature extraction and comparison of biometric data and the biometric decision-making process; — use of biometric technology for non-financial transaction applications, such as physical or logical system access control.

This document describes the management of symmetric and asymmetric cryptographic keys that can be used to protect sensitive information in financial services related to retail payments. The document covers all aspects of retail financial services, including connections between a card-accepting device and an Acquirer, between an Acquirer and a card Issuer, and between an ICC and a card-accepting device. It covers all phases of the key life cycle, including the generation, distribution, utilization, archiving, replacement and destruction of the keying material. This document covers manual and automated management of keying material, and any combination thereof, used for retail financial services. It includes guidance and requirements related to key separation, substitution prevention, identification, synchronization, integrity, confidentiality and compromise, as well as logging and auditing of key management events. Requirements associated with hardware used to manage keys have also been included in this document.

This document specifies procedures, independent of the transmission process, for protecting the integrity of transmitted financial-service-related messages and for verifying that a message has originated from an authorized source, or that stored data has retained integrity. A list of block ciphers approved for the calculation of a message authentication code (MAC) is also provided. The authentication methods defined in this document are applicable to stored data and to messages formatted and transmitted both as coded character sets or as binary data. This document is designed for use with symmetric algorithms where both sender and receiver use the same key. It does not specify methods for establishing the shared key. Its application will not protect the user against internal fraud perpetrated by the sender or the receiver, nor against forgery of a MAC by the receiver.

This document describes a data element related to key management which can be transmitted either in transaction messages to convey information about cryptographic keys used to secure the current transaction, or in cryptographic service messages to convey information about cryptographic keys to be used to secure future transactions. This document addresses the requirements for the use of the data element related to key management within ISO 8583-1, using the following two ISO 8583-1 data elements for DEA and TDEA: — security related control information (data element 53); — key management data (data element 96). The data element related to key management for DEA and TDEA is constructed from the concatenation of two ISO 8583-1 message elements, data element 53 — security related control information, and data element 96 — key management data. It conveys information about the associated transaction's cryptographic key(s) and is divided into subfields including a control field, a key-set identifier and additional optional information. For AES implementations, the data elements are summarized in one field. This document is applicable to either symmetric or asymmetric cipher systems.

ISO 9564-1:2017 specifies the basic principles and techniques which provide the minimum security measures required for effective international PIN management. These measures are applicable to those institutions responsible for implementing techniques for the management and protection of PINs during their creation, issuance, usage and deactivation. ISO 9564-1:2017 is applicable to the management of cardholder PINs for use as a means of cardholder verification in retail banking systems in, notably, automated teller machine (ATM) systems, point-of-sale (POS) terminals, automated fuel dispensers, vending machines, banking kiosks and PIN selection/change systems. It is applicable to issuer and interchange environments. The provisions of ISO 9564-1:2017 are not intended to cover: a) PIN management and security in environments where no persistent cryptographic relationship exists between the transaction-origination device and the acquirer, e.g. use of a browser for online shopping (for these environments, see ISO 9564-4); b) protection of the PIN against loss or intentional misuse by the customer; c) privacy of non-PIN transaction data; d) protection of transaction messages against alteration or substitution; e) protection against replay of the PIN or transaction; f) specific key management techniques; g) offline PIN verification used in contactless devices; h) requirements specifically associated with PIN management as it relates to multi-application functionality in an ICC.

ISO 13491-1:2016 specifies the security characteristics for secure cryptographic devices (SCDs) based on the cryptographic processes defined in ISO 9564, ISO 16609, and ISO 11568. ISO 13491-1:2016 has two primary purposes: - to state the security characteristics concerning both the operational characteristics of SCDs and the management of such devices throughout all stages of their life cycle; ? to provide guidance for methodologies to verify compliance with those requirements. This information is contained in Annex A. ISO 13491-2 specifies checklists to be used to evaluate secure cryptographic devices (SCDs) incorporating cryptographic processes as specified in ISO 9564-1, ISO 9564-2, ISO 16609, ISO 11568-1, ISO 11568-2, ISO 11568-3, ISO 11568-4, ISO 11568-5, and ISO 11568-6 in the financial services environment. Annex A provides an informative illustration of the concepts of security levels described in this part of ISO 13491 as being applicable to SCDs. ISO 13491-1:2016 does not address issues arising from the denial of service of an SCD. Specific requirements for the security characteristics and management of specific types of SCD functionality used in the retail financial services environment are contained in ISO 13491‑2.

ISO 9564-4:2016 provides requirements for the use of personal identification numbers (PIN) in eCommerce. The PINs in scope are the same cardholder PINs used as a means of cardholder verification in card-based financial transactions; notably, automated teller machine (ATM) systems, point-of-sale (POS) terminals, automated fuel dispensers, and vending machines. It is applicable to financial card-originated transactions requiring verification of the PIN and to those organizations responsible for implementing techniques for the management of the PIN in eCommerce. The provisions of this part of ISO 9564 are not intended to cover - passwords, passcodes, pass phrases and other shared secrets used for customer authentication in online banking, telephone banking, digital wallets, mobile payment, etc., - management of cardholder PINs for use as a means of cardholder verification in retail banking systems in, notably, automated teller machine (ATM) systems, point-of-sale (POS) terminals, automated fuel dispensers, vending machines, banking kiosks and PIN selection/change systems, which are covered in ISO 9564‑1, - card proxies such as mobile phones or key fobs, - approved algorithms for PIN encipherment, which are covered in ISO 9564‑2, - the protection of the PIN against loss or intentional misuse by the customer or authorized employees of the issuer, - privacy of non-PIN transaction data, - protection of transaction messages against alteration or substitution, e.g. an online authorization response, - protection against replay of the transaction, - functionality of devices used for PIN entry which is related to issuer functions other than PIN entry, - specific key management techniques, and - access to, and storage of, card data other than the PIN by applications such as wallets.

ISO 9564-2:2014 specifies approved algorithms for the encipherment of Personal Identification Numbers (PINs).

ISO 13491-2:2017 specifies checklists to be used to evaluate secure cryptographic devices (SCDs) incorporating cryptographic processes as specified in ISO 9564‑1, ISO 9564‑2, ISO 16609, ISO 11568‑1, ISO 11568‑2, and ISO 11568‑4 in the financial services environment. Integrated circuit (IC) payment cards are subject to the requirements identified in this document up until the time of issue after which they are to be regarded as a "personal" device and outside of the scope of this document. ISO 13491-2:2017 does not address issues arising from the denial of service of an SCD. In the checklists given in Annex A to Annex H, the term "not feasible" is intended to convey the notion that although a particular attack might be technically possible, it would not be economically viable since carrying out the attack would cost more than any benefits obtained from a successful attack. In addition to attacks for purely economic gain, malicious attacks directed toward loss of reputation need to be considered.

ISO 13491-2:2016 specifies checklists to be used to evaluate secure cryptographic devices (SCDs) incorporating cryptographic processes as specified in H.5, ISO 9564‑2, ISO 16609, ISO 11568‑1, ISO 11568‑2, and ISO 11568‑4 in the financial services environment. IC payment cards are subject to the requirements identified in this part of ISO 13491 up until the time of issue after which they are to be regarded as a "personal" device and outside of the scope of this part of ISO 13491. ISO 13491-2:2016 does not address issues arising from the denial of service of an SCD. In the checklists given in Annexes A to H, the term "not feasible" is intended to convey the notion that although a particular attack might be technically possible, it would not be economically viable since carrying out the attack would cost more than any benefits obtained from a successful attack. In addition to attacks for purely economic gain, malicious attacks directed toward loss of reputation need to be considered.

1 Scope This part of ISO 11568 specifies techniques for the protection of symmetric and asymmetric cryptographic keys in a retail banking environment using symmetric ciphers and the life-cycle management of the associated symmetric keys. The techniques described enable compliance with the principles described in ISO 11568-1. The techniques described are applicable to any symmetric key management operation. The notation used in this part of ISO 11568 is given in Annex A. Algorithms approved for use with the techniques described in this part of ISO 11568 are given in Annex B.

ISO 9564-1:2011 specifies the basic principles and techniques which provide the minimum security measures required for effective international personal identification number (PIN) management. These measures are applicable to those institutions responsible for implementing techniques for the management and protection of PINs during their creation, issuance, usage and deactivation. ISO 9564-1:2011 is applicable to the management of cardholder PINs for use as a means of cardholder verification in retail banking systems in, notably, automated teller machine (ATM) systems, point-of-sale (POS) terminals, automated fuel dispensers, vending machines, banking kiosks and PIN selection/change systems. It is applicable to issuer and interchange environments. The provisions of ISO 9564-1:2011 are not intended to cover: a) PIN management and security in environments where no persistent cryptographic relationship exists between the transaction-origination device and the acquirer, e.g. use of a browser for online shopping; b) protection of the PIN against loss or intentional misuse by the customer; c) privacy of non-PIN transaction data; d) protection of transaction messages against alteration or substitution; e) protection against replay of the PIN or transaction; f) specific key management techniques; g) offline PIN verification used in contactless devices; h) requirements specifically associated with PIN management as it relates to multi-application functionality in integrated circuit (IC) cards.

ISO 19092:2008 describes the security framework for using biometrics for authentication of individuals in financial services. It introduces the types of biometric technologies and addresses issues concerning their application. ISO 19092:2008 also describes the architectures for implementation, specifies the minimum security requirements for effective management, and provides control objectives and recommendations suitable for use by a professional practitioner. The following are within the scope of ISO 19092:2008: usage of biometrics for the authentication of employees and persons seeking financial services by: verification of a claimed identity; identification of an individual; validation of credentials presented at enrolment to support authentication as required by risk management; management of biometric information across its life cycle comprised of the enrolment, transmission and storage, verification, identification and termination processes; security of biometric information during its life cycle, encompassing data integrity, origin authentication and confidentiality; application of biometrics for logical and physical access control; surveillance to protect the financial institution and its customers; security of the physical hardware used throughout the biometric information life cycle. ISO 19092:2008 provides the mandatory means whereby biometric information may be encrypted for data confidentiality or other reasons.

ISO 11568-4:2007 specifies techniques for the protection of symmetric and asymmetric cryptographic keys in a retail financial services environment using asymmetric cryptosystems and the life-cycle management of the associated asymmetric keys. The techniques described in this part of ISO 11568 enable compliance with the principles described in ISO 11568-1. For the purposes of this document, the retail financial services environment is restricted to the interface between: a card-accepting device and an acquirer; an acquirer and a card issuer; an ICC and a card-accepting device.

ISO 13491-1:2007 specifies the requirements for secure cryptographic devices (SCDs) based on the cryptographic processes defined in ISO 9564, ISO 16609 and ISO 11568. ISO 13491-1:2007 has two primary purposes: to state the requirements concerning both the operational characteristics of SCDs and the management of such devices throughout all stages of their life cycle, and to standardize the methodology for verifying compliance with those requirements. Appropriate device characteristics are necessary to ensure that the device has the proper operational capabilities and provides adequate protection for the data it contains. Appropriate device management is necessary to ensure that the device is legitimate, that it has not been modified in an unauthorized manner (e.g. by “bugging”) and that any sensitive data placed within the device (e.g. cryptographic keys) has not been subject to disclosure or change. Absolute security is not achievable in practical terms. Cryptographic security depends upon each life cycle phase of the SCD and the complementary combination of appropriate management procedures and secure cryptographic characteristics. These management procedures implement preventive measures to reduce the opportunity for a breach of SCD security. These aim for a high probability of detection of any unauthorized access to sensitive or confidential data, should device characteristics fail to prevent or detect the security compromise. Annex A provides an informative illustration of the concepts of security levels described in ISO 13491-1:2007 as being applicable to SCDs.

ISO TR 13569:2005 provides guidelines on the development of an information security programme for institutions in the financial services industry. It includes discussion of the policies, organization and the structural, legal and regulatory components of such a programme. Considerations for the selection and implementation of security controls, and the elements required to manage information security risk within a modern financial services institution are discussed. Recommendations are given that are based on consideration of the institutions' business environment, practices and procedures. Included in this guidance is a discussion of legal and regulatory compliance issues, which should be considered in the design and implementation of the programme.

ISO 11568-1:2005 specifies the principles for the management of keys used in cryptosystems implemented within the retail-banking environment. The retail-banking environment includes the interface between a card accepting device and an acquirer, an acquirer and a card issuer, an ICC and a card-accepting device. An example of this environment and threats associated with the implementation of ISO 11568-1:2005 in the retail-banking environment are also described. ISO 11568-1:2005 is applicable both to the keys of symmetric cipher systems, where both originator and recipient use the same secret key(s), and to the private and public keys of asymmetric cryptosystems, unless otherwise stated. The procedure for the approval of cryptographic algorithms used for key management is specified. The use of ciphers often involves control information other than keys, e.g. initialization vectors and key identifiers. This other information is collectively called "keying material". Although ISO 11568-1:2005 specifically addresses the management of keys, the principles, services, and techniques applicable to keys may also be applicable to keying material. ISO 11568-1:2005 is appropriate for use by financial institutions and other organizations engaged in the area of retail financial services, where the interchange of information requires confidentiality, integrity, or authentication. Retail financial services include but are not limited to such processes as POS debit and credit authorizations, automated dispensing machine and ATM transactions, etc. ISO 9564 and ISO 16609 specify the use of cryptographic operations within retail financial transactions for personal identification number (PIN) encipherment and message authentication, respectively. The ISO 11568 series of standards is applicable to the management of the keys introduced by those standards. Additionally, the key management procedures may themselves require the introduction of further keys, e.g. key encipherment keys. The key management procedures are equally applicable to those keys.

ISO 13491-2:2005 specifies checklists to be used to evaluate secure cryptographic devices (SCDs) incorporating cryptographic processes, as specified in parts 1 and 2 of ISO 9564, ISO 16609 and parts 1 to 6 of ISO 11568, in the financial services environment. IC payment cards are subject to the requirements identified in this part of ISO 13491 up until the time of issue, after which they are to be regarded as a "personal" device and outside of the scope of this document. ISO 13491-2:2005 does not address issues arising from the denial of service of an SCD.

ISO 9564-2:2005 specifies algorithms for the encipherment of Personal Identification Numbers (PINs). Based on the approval processes established in ISO 9564-1, these are the data encryption algorithm (DEA) and the RSA encryption algorithm.

ISO/TR 9564-4:2004 provides guidelines for personal identification number PIN handling in open networks, presenting finance industry best-practice security measures for PIN management and the handling of financial card originated transactions in environments where issuers and acquirers have no direct control over management, or where no relationship exists between the PIN entry device and the acquirer prior to the transaction.