## Abstract

This document defines all the strings and constants reserved by FIDO protocols. The values defined in this document are referenced by various FIDO specifications.

## Status of This Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current FIDO Alliance publications and the latest revision of this technical report can be found in the FIDO Alliance specifications index at https://www.fidoalliance.org/specifications/.

This document was published by the FIDO Alliance as a Implementation Draft. This document is intended to become a FIDO Alliance Proposed Standard. If you wish to make comments regarding this document, please Contact Us. All comments are welcome.

IMPLEMENTATION DRAFT

This Implementation Draft Specification has been prapared by FIDO Alliance, Inc. Permission is hereby granted to use the Specification solely for the purpose of implementing the Specification. No rights are granted to prepare derivative works of this Specification. Entities seeking permission to reproduce portions of this Specification for other uses must contact the FIDO Alliance to determine whether an appropriate license for such use is available.

Implementation of certain elements of this Specification may require licenses under third party intellectual property rights, including without limitation, patent rights. The FIDO Alliance, Inc. and its Members and any other contributors to the Specification are not, and shall not be held, responsible in any manner for identifying or failing to identify any or all such third party intellectual property rights.

THIS FIDO ALLIANCE SPECIFICATION IS PROVIDED “AS IS” AND WITHOUT ANY WARRANTY OF ANY KIND, INCLUDING, WITHOUT LIMITATION, ANY EXPRESS OR IMPLIED WARRANTY OF NON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

## Table of Contents

## 1. Notation

Type names, attribute names and element names are written as `code`.

String literals are enclosed in “”, e.g. “UAF-TLV”.

In formulas we use “|” to denote byte wise concatenation operations.

FIDO specific terminology used in this document is defined in [FIDOGlossary].

Some entries are marked as "(optional)" in this spec. The meaning of this is defined in other FIDO specifications referring to this document.

### 1.1 Conformance

As well as sections marked as non-normative, all authoring guidelines, diagrams, examples, and notes in this specification are non-normative. Everything else in this specification is normative.

The key words MUST, MUST NOT, REQUIRED, SHOULD, SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL in this specification are to be interpreted as described in [RFC2119].

## 2. Overview

This section is non-normative.

This document defines the registry of FIDO-specific constants common to multiple FIDO protocol families. It is expected that, over time, new constants will be added to this registry. For example new authentication algorithms and new types of authenticator characteristics will require new constants to be defined for use within the specifications.

## 3. Authenticator Characteristics

This section is normative.

### 3.1 User Verification Methods

The `USER_VERIFY` constants are flags in a bitfield represented as a 32 bit long integer. They describe the methods and capabilities of an UAF authenticator for locally verifying a user. The operational details of these methods are opaque to the server. These constants are used in the authoritative metadata for an authenticator, reported and queried through the UAF Discovery APIs, and used to form authenticator policies in UAF protocol messages.

All user verification methods must be performed locally by the authenticator in order to meet FIDO privacy principles.

`USER_VERIFY_PRESENCE` `0x00000001`
  This flag MUST be set if the authenticator is able to confirm user presence in any fashion. If this flag and no other is set for user verification, the guarantee is only that the authenticator cannot be operated without some human intervention, not necessarily that the presence verification provides any level of authentication of the human's identity. (e.g. a device that requires a touch to activate)
`USER_VERIFY_FINGERPRINT` `0x00000002`
  This flag MUST be set if the authenticator uses any type of measurement of a fingerprint for user verification.
`USER_VERIFY_PASSCODE` `0x00000004`
  This flag MUST be set if the authenticator uses a local-only passcode (i.e. a passcode not known by the server) for user verification.
`USER_VERIFY_VOICEPRINT` `0x00000008`
  This flag MUST be set if the authenticator uses a voiceprint (also known as speaker recognition) for user verification.
`USER_VERIFY_FACEPRINT` `0x00000010`
  This flag MUST be set if the authenticator uses any manner of face recognition to verify the user.
`USER_VERIFY_LOCATION` `0x00000020`
  This flag MUST be set if the authenticator uses any form of location sensor or measurement for user verification.
`USER_VERIFY_EYEPRINT` `0x00000040`
  This flag MUST be set if the authenticator uses any form of eye biometrics for user verification.
`USER_VERIFY_PATTERN` `0x00000080`
  This flag MUST be set if the authenticator uses a drawn pattern for user verification.
`USER_VERIFY_HANDPRINT` `0x00000100`
  This flag MUST be set if the authenticator uses any measurement of a full hand (including palm-print, hand geometry or vein geometry) for user verification.
`USER_VERIFY_NONE` `0x00000200`
  This flag MUST be set if the authenticator will respond without any user interaction (e.g. Silent Authenticator).
`USER_VERIFY_ALL` `0x00000400`
  If an authenticator sets multiple flags for user verification types, it MAY also set this flag to indicate that all verification methods will be enforced (e.g. faceprint AND voiceprint). If flags for multiple user verification methods are set and this flag is not set, verification with only one is necessary (e.g. fingerprint OR passcode).

### 3.2 Key Protection Types

The `KEY_PROTECTION` constants are flags in a bit field represented as a 16 bit long integer. They describe the method an authenticator uses to protect the private key material for FIDO registrations. Refer to [UAFAuthnrCommands] for more details on the relevance of keys and key protection. These constants are used in the authoritative metadata for an authenticator, reported and queried through the UAF Discovery APIs, and used to form authenticator policies in UAF protocol messages.

When used in metadata describing an authenticator, several of these flags are exclusive of others (i.e. can not be combined) - the certified metadata may have at most one of the mutually exclusive bits set to 1. When used in authenticator policy, any bit may be set to 1, e.g. to indicate that a server is willing to accept authenticators using either `KEY_PROTECTION_SOFTWARE` or `KEY_PROTECTION_HARDWARE`.

Note

These flags must be set according to the effective security of the keys, in order to follow the assumptions made in [FIDOSecRef]. For example, if a key is stored in a secure element but software running on the FIDO User Device could call a function in the secure element to export the key either in the clear or using an arbitrary wrapping key, then the effective security is `KEY_PROTECTION_SOFTWARE` and not `KEY_PROTECTION_SECURE_ELEMENT`.

`KEY_PROTECTION_SOFTWARE` `0x0001`
  This flag MUST be set if the authenticator uses software-based key management. Exclusive in authenticator metadata with `KEY_PROTECTION_HARDWARE`, `KEY_PROTECTION_TEE`, `KEY_PROTECTION_SECURE_ELEMENT`
`KEY_PROTECTION_HARDWARE` `0x0002`
  This flag SHOULD be set if the authenticator uses hardware-based key management. Exclusive in authenticator metadata with `KEY_PROTECTION_SOFTWARE`
`KEY_PROTECTION_TEE` `0x0004`
  This flag SHOULD be set if the authenticator uses the Trusted Execution Environment [TEE] for key management. In authenticator metadata, this flag should be set in conjunction with `KEY_PROTECTION_HARDWARE`. Mutually exclusive in authenticator metadata with `KEY_PROTECTION_SOFTWARE`, `KEY_PROTECTION_SECURE_ELEMENT`
`KEY_PROTECTION_SECURE_ELEMENT` `0x0008`
  This flag SHOULD be set if the authenticator uses a Secure Element [SecureElement] for key management. In authenticator metadata, this flag should be set in conjunction with `KEY_PROTECTION_HARDWARE`. Mutually exclusive in authenticator metadata with `KEY_PROTECTION_TEE`, `KEY_PROTECTION_SOFTWARE`
`KEY_PROTECTION_REMOTE_HANDLE` `0x0010`
  This flag MUST be set if the authenticator does not store (wrapped) UAuth keys at the client, but relies on a server-provided key handle. This flag MUST be set in conjunction with one of the other `KEY_PROTECTION` flags to indicate how the local key handle wrapping key and operations are protected. Servers MAY unset this flag in authenticator policy if they are not prepared to store and return key handles, for example, if they have a requirement to respond indistinguishably to authentication attempts against userIDs that do and do not exist. Refer to [UAFProtocol] for more details.

### 3.3 Matcher Protection Types

The `MATCHER_PROTECTION` constants are flags in a bit field represented as a 16 bit long integer. They describe the method an authenticator uses to protect the matcher that performs user verification. These constants are used in the authoritative metadata for an authenticator, reported and queried through the UAF Discovery APIs, and used to form authenticator policies in UAF protocol messages. Refer to [UAFAuthnrCommands] for more details on the matcher component.

Note

These flags must be set according to the effective security of the matcher, in order to follow the assumptions made in [FIDOSecRef]. For example, if a passcode based matcher is implemented in a secure element, but the passcode is expected to be provided as unauthenticated parameter, then the effective security is `MATCHER_PROTECTION_SOFTWARE` and not `MATCHER_PROTECTION_ON_CHIP`.

`MATCHER_PROTECTION_SOFTWARE` `0x0001`
  This flag MUST be set if the authenticator's matcher is running in software. Exclusive in authenticator metadata with `MATCHER_PROTECTION_TEE`, `MATCHER_PROTECTION_ON_CHIP`
`MATCHER_PROTECTION_TEE` `0x0002`
  This flag SHOULD be set if the authenticator's matcher is running inside the Trusted Execution Environment [TEE]. Mutually exclusive in authenticator metadata with `MATCHER_PROTECTION_SOFTWARE`, `MATCHER_PROTECTION_ON_CHIP`
`MATCHER_PROTECTION_ON_CHIP` `0x0004`
  This flag SHOULD be set if the authenticator's matcher is running on the chip. Mutually exclusive in authenticator metadata with `MATCHER_PROTECTION_TEE`, `MATCHER_PROTECTION_SOFTWARE`

### 3.4 Authenticator Attachment Hints

The `ATTACHMENT_HINT` constants are flags in a bit field represented as a 32 bit long. They describe the method an authenticator uses to communicate with the FIDO User Device. These constants are reported and queried through the UAF Discovery APIs [UAFAppAPIAndTransport], and used to form Authenticator policies in UAF protocol messages. Because the connection state and topology of an authenticator may be transient, these values are only hints that can be used by server-supplied policy to guide the user experience, e.g. to prefer a device that is connected and ready for authenticating or confirming a low-value transaction, rather than one that is more secure but requires more user effort.

Note

These flags are not a mandatory part of authenticator metadata and, when present, only indicate possible states that may be reported during authenticator discovery.

`ATTACHMENT_HINT_INTERNAL` `0x0001`
  This flag MAY be set to indicate that the authenticator is permanently attached to the FIDO User Device.

  A device such as a smartphone may have authenticator functionality that is able to be used both locally and remotely. In such a case, the FIDO client MUST filter and exclusively report only the relevant bit during Discovery and when performing policy matching.

  This flag cannot be combined with any other `ATTACHMENT_HINT` flags.

`ATTACHMENT_HINT_EXTERNAL` `0x0002`
  This flag MAY be set to indicate, for a hardware-based authenticator, that it is removable or remote from the FIDO User Device.

  A device such as a smartphone may have authenticator functionality that is able to be used both locally and remotely. In such a case, the FIDO UAF Client MUST filter and exclusively report only the relevant bit during discovery and when performing policy matching.

`ATTACHMENT_HINT_WIRED` `0x0004`
  This flag MAY be set to indicate that an external authenticator currently has an exclusive wired connection, e.g. through USB, Firewire or similar, to the FIDO User Device.
`ATTACHMENT_HINT_WIRELESS` `0x0008`
  This flag MAY be set to indicate that an external authenticator communicates with the FIDO User Device through a personal area or otherwise non-routed wireless protocol, such as Bluetooth or NFC.
`ATTACHMENT_HINT_NFC` `0x0010`
  This flag MAY be set to indicate that an external authenticator is able to communicate by NFC to the FIDO User Device. As part of authenticator metadata, or when reporting characteristics through discovery, if this flag is set, the `ATTACHMENT_HINT_WIRELESS` flag SHOULD also be set as well.
`ATTACHMENT_HINT_BLUETOOTH` `0x0020`
  This flag MAY be set to indicate that an external authenticator is able to communicate using Bluetooth with the FIDO User Device. As part of authenticator metadata, or when reporting characteristics through discovery, if this flag is set, the `ATTACHMENT_HINT_WIRELESS` flag SHOULD also be set.
`ATTACHMENT_HINT_NETWORK` `0x0040`
  This flag MAY be set to indicate that the authenticator is connected to the FIDO User Device over a non-exclusive network (e.g. over a TCP/IP LAN or WAN, as opposed to a PAN or point-to-point connection).
`ATTACHMENT_HINT_READY` `0x0080`
  This flag MAY be set to indicate that an external authenticator is in a "ready" state. This flag is set by the ASM at its discretion.
  Note

  Generally this should indicate that the device is immediately available to perform user verification without additional actions such as connecting the device or creating a new biometric profile enrollment, but the exact meaning may vary for different types of devices. For example, a USB authenticator may only report itself as ready when it is plugged in, or a Bluetooth authenticator when it is paired and connected, but an NFC-based authenticator may always report itself as ready.

`ATTACHMENT_HINT_WIFI_DIRECT` `0x0100`
  This flag MAY be set to indicate that an external authenticator is able to communicate using WiFi Direct with the FIDO User Device. As part of authenticator metadata and when reporting characteristics through discovery, if this flag is set, the `ATTACHMENT_HINT_WIRELESS` flag SHOULD also be set.

### 3.5 Transaction Confirmation Display Types

The `TRANSACTION_CONFIRMATION_DISPLAY` constants are flags in a bit field represented as a 16 bit long integer. They describe the availability and implementation of a transaction confirmation display capability required for the transaction confirmation operation. These constants are used in the authoritative metadata for an authenticator, reported and queried through the UAF Discovery APIs, and used to form authenticator policies in UAF protocol messages. Refer to [UAFAuthnrCommands] for more details on the security aspects of TransactionConfirmation Display.

`TRANSACTION_CONFIRMATION_DISPLAY_ANY` `0x0001`
  This flag MUST be set to indicate that a transaction confirmation display, of any type, is available on this authenticator. Other `TRANSACTION_CONFIRMATION_DISPLAY` flags MAY also be set if this flag is set. If the authenticator does not support a transaction confirmation display, then the value of `TRANSACTION_CONFIRMATION_DISPLAY` MUST be set to 0.
`TRANSACTION_CONFIRMATION_DISPLAY_PRIVILEGED_SOFTWARE` `0x0002`
  This flag MUST be set to indicate, that a software-based transaction confirmation display operating in a privileged context is available on this authenticator.

  A FIDO client that is capable of providing this capability MAY set this bit (in conjunction with `TRANSACTION_CONFIRMATION_DISPLAY_ANY`) for all authenticators of type `ATTACHMENT_HINT_INTERNAL`, even if the authoritative metadata for the authenticator does not indicate this capability.

  Note

  Software based transaction confirmation displays might be implemented within the boundaries of the ASM rather than by the authenticator itself [UAFASM].

  This flag is mutually exclusive with `TRANSACTION_CONFIRMATION_DISPLAY_TEE` and `TRANSACTION_CONFIRMATION_DISPLAY_HARDWARE`.
`TRANSACTION_CONFIRMATION_DISPLAY_TEE` `0x0004`
  This flag SHOULD be set to indicate that the authenticator implements a transaction confirmation display in a Trusted Execution Environment ([TEE], [TEESecureDisplay]). This flag is mutually exclusive with `TRANSACTION_CONFIRMATION_DISPLAY_PRIVILEGED_SOFTWARE` and `TRANSACTION_CONFIRMATION_DISPLAY_HARDWARE`.
`TRANSACTION_CONFIRMATION_DISPLAY_HARDWARE` `0x0008`
  This flag SHOULD be set to indicate that a transaction confirmation display based on hardware assisted capabilities is available on this authenticator. This flag is mutually exclusive with `TRANSACTION_CONFIRMATION_DISPLAY_PRIVILEGED_SOFTWARE` and `TRANSACTION_CONFIRMATION_DISPLAY_TEE`.
`TRANSACTION_CONFIRMATION_DISPLAY_REMOTE` `0x0010`
  This flag SHOULD be set to indicate that the transaction confirmation display is provided on a distinct device from the FIDO User Device. This flag can be combined with any other flag.

### 3.6 Tags used for crypto algorithms and types

These tags indicate the specific authentication algorithms, public key formats and other crypto relevant data.

#### 3.6.1 Authentication Algorithms

The `ALG_SIGN` constants are 16 bit long integers indicating the specific signature algorithm and encoding.

Note

FIDO UAF supports RAW and DER signature encodings in order to allow small footprint authenticator implementations.

`ALG_SIGN_SECP256R1_ECDSA_SHA256_RAW` `0x0001`
  An ECDSA signature on the NIST secp256r1 curve which MUST have raw R and S buffers, encoded in big-endian order. This is the signature encoding as specified in [ECDSA-ANSI].

  I.e. `[R (32 bytes), S (32 bytes)]`

  This algorithm is suitable for authenticators using the following key representation formats:

  - ALG_KEY_ECC_X962_RAW
  - ALG_KEY_ECC_X962_DER
`ALG_SIGN_SECP256R1_ECDSA_SHA256_DER` `0x0002`
  DER [ITU-X690-2008] encoded ECDSA signature [RFC5480] on the NIST secp256r1 curve.

  I.e. a DER encoded `SEQUENCE { r INTEGER, s INTEGER }`

  This algorithm is suitable for authenticators using the following key representation formats:

  - ALG_KEY_ECC_X962_RAW
  - ALG_KEY_ECC_X962_DER
`ALG_SIGN_RSASSA_PSS_SHA256_RAW` `0x0003`
  RSASSA-PSS [RFC3447] signature MUST have raw S buffers, encoded in big-endian order [RFC4055] [RFC4056]. The default parameters as specified in [RFC4055] MUST be assumed, i.e.
  - Mask Generation Algorithm MGF1 with SHA256
  - Salt Length of 32 bytes, i.e. the length of a SHA256 hash value.
  - Trailer Field value of 1, which represents the trailer field with hexadecimal value `0xBC`.

  I.e. `[ S (256 bytes) ]`

  This algorithm is suitable for authenticators using the following key representation formats:

  - ALG_KEY_RSA_2048_RAW
  - ALG_KEY_RSA_2048_DER
`ALG_SIGN_RSASSA_PSS_SHA256_DER` `0x0004`
  DER [ITU-X690-2008] encoded OCTET STRING (not BIT STRING!) containing the RSASSA-PSS [RFC3447] signature [RFC4055] [RFC4056]. The default parameters as specified in [RFC4055] MUST be assumed, i.e.
  - Mask Generation Algorithm MGF1 with SHA256
  - Salt Length of 32 bytes, i.e. the length of a SHA256 hash value.
  - Trailer Field value of 1, which represents the trailer field with hexadecimal value `0xBC`.

  I.e. a DER encoded `OCTET STRING` (including its tag and length bytes).

  This algorithm is suitable for authenticators using the following key representation formats:

  - ALG_KEY_RSA_2048_RAW
  - ALG_KEY_RSA_2048_DER
`ALG_SIGN_SECP256K1_ECDSA_SHA256_RAW` `0x0005`
  An ECDSA signature on the secp256k1 curve which MUST have raw R and S buffers, encoded in big-endian order.

  I.e.`[R (32 bytes), S (32 bytes)]`

  This algorithm is suitable for authenticators using the following key representation formats:

  - ALG_KEY_ECC_X962_RAW
  - ALG_KEY_ECC_X962_DER
`ALG_SIGN_SECP256K1_ECDSA_SHA256_DER` `0x0006`
  DER [ITU-X690-2008] encoded ECDSA signature [RFC5480] on the secp256k1 curve.

  I.e. a DER encoded `SEQUENCE { r INTEGER, s INTEGER }`

  This algorithm is suitable for authenticators using the following key representation formats:

  - ALG_KEY_ECC_X962_RAW
  - ALG_KEY_ECC_X962_DER
`ALG_SIGN_SM2_SM3_RAW` `0x0007` (optional)
  Chinese SM2 elliptic curve based signature algorithm combined with SM3 hash algorithm [OSCCA-SM2][OSCCA-SM3]. We use the 256bit curve [OSCCA-SM2-curve-param].

  This algorithm is suitable for authenticators using the following key representation format: ALG_KEY_ECC_X962_RAW.

`ALG_SIGN_RSA_EMSA_PKCS1_SHA256_RAW` `0x0008`
  This is the EMSA-PKCS1-v1_5 signature as defined in [RFC3447]. This means that the encoded message EM will be the input to the cryptographic signing algorithm RSASP1 as defined in [RFC3447]. The result s of RSASP1 is then encoded using function I2OSP to produce the raw signature octets.
  - `EM = 0x00 | 0x01 | PS | 0x00 | T`
  - with the padding string PS with length=emLen - tLen - 3 octets having the value 0xff for each octet, e.g. `(0x) ff ff ff ff ff ff ff ff`
  - with the DER [ITU-X690-2008] encoded DigestInfo value T: `(0x)30 31 30 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04 20 | H`, where H denotes the bytes of the SHA256 hash value.

  This algorithm is suitable for authenticators using the following key representation formats:

  - ALG_KEY_RSA_2048_RAW
  - ALG_KEY_RSA_2048_DER
  Note

  Implementers should verify that their implementation of the PKCS#1 V1.5 signature follows the recommendations in [RFC3218] to protect against adaptive chosen-ciphertext attacks such as Bleichenbacher.

`ALG_SIGN_RSA_EMSA_PKCS1_SHA256_DER` `0x0009`
  DER [ITU-X690-2008] encoded OCTET STRING (not BIT STRING!) containing the EMSA-PKCS1-v1_5 signature as defined in [RFC3447]. This means that the encoded message EM will be the input to the cryptographic signing algorithm RSASP1 as defined in [RFC3447]. The result s of RSASP1 is then encoded using function I2OSP to produce the raw signature. The raw signature is DER [ITU-X690-2008] encoded as an OCTET STRING to produce the final signature octets.
  - `EM = 0x00 | 0x01 | PS | 0x00 | T`
  - with the padding string PS with length=emLen - tLen - 3 octets having the value 0xff for each octet, e.g. `(0x) ff ff ff ff ff ff ff ff`
  - with the DER encoded DigestInfo value T: `(0x)30 31 30 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04 20 | H`, where H denotes the bytes of the SHA256 hash value.

  This algorithm is suitable for authenticators using the following key representation formats:

  - ALG_KEY_RSA_2048_RAW
  - ALG_KEY_RSA_2048_DER
  Note

  Implementers should verify that their implementation of the PKCS#1 V1.5 signature follows the recommendations in [RFC3218] to protect against adaptive chosen-ciphertext attacks such as Bleichenbacher.

#### 3.6.2 Public Key Representation Formats

The `ALG_KEY` constants are 16 bit long integers indicating the specific Public Key algorithm and encoding.

Note

FIDO UAF supports RAW and DER encodings in order to allow small footprint authenticator implementations. By definition, the authenticator must encode the public key as part of the registration assertion.

`ALG_KEY_ECC_X962_RAW` `0x0100`
  Raw ANSI X9.62 formatted Elliptic Curve public key [SEC1].

  I.e. `[0x04, X (32 bytes), Y (32 bytes)]`. Where the byte `0x04` denotes the uncompressed point compression method.

`ALG_KEY_ECC_X962_DER` `0x0101`
  DER [ITU-X690-2008] encoded ANSI X.9.62 formatted `SubjectPublicKeyInfo` [RFC5480] specifying an elliptic curve public key.

  I.e. a DER encoded `SubjectPublicKeyInfo` as defined in [RFC5480].

  Authenticator implementations MUST generate `namedCurve` in the `ECParameters` object which is included in the `AlgorithmIdentifier`. A FIDO UAF Server MUST accept `namedCurve` in the `ECParameters` object which is included in the `AlgorithmIdentifier`.

`ALG_KEY_RSA_2048_RAW` `0x0102`
  Raw encoded 2048-bit RSA public key [RFC3447].

  That is, `[n (256 bytes), e (N-256 bytes)]`. Where `N` is the total length of the field.

  This total length should be taken from the object containing this key, e.g. the TLV encoded field.

`ALG_KEY_RSA_2048_DER` `0x0103`
  ASN.1 DER [ITU-X690-2008] encoded 2048-bit RSA [RFC3447] public key [RFC4055].

  That is a DER encoded `SEQUENCE { n INTEGER, e INTEGER }`.

## A. References

### A.1 Normative references

[FIDOGlossary]
  R. Lindemann, D. Baghdasaryan, B. Hill, J. Hodges, FIDO Technical Glossary. FIDO Alliance Proposed Standard. URLs:
  HTML: https://fidoalliance.org/specs/fido-u2f-v1.1-id-20160915/fido-glossary-v1.1-id-20160915.html
  PDF: https://fidoalliance.org/specs/fido-u2f-v1.1-id-20160915/fido-glossary-v1.1-id-20160915.pdf
[ITU-X690-2008]
  X.690: Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER), (T-REC-X.690-200811). International Telecommunications Union, November 2008 URL: http://www.itu.int/rec/T-REC-X.690-200811-I/en
[OSCCA-SM2]
  SM2: Public Key Cryptographic Algorithm SM2 Based on Elliptic Curves: Part 1: General. December 2010. URL: http://www.oscca.gov.cn/UpFile/2010122214822692.pdf
[OSCCA-SM2-curve-param]
  SM2: Elliptic Curve Public-Key Cryptography Algorithm: Recommended Curve Parameters. December 2010. URL: http://www.oscca.gov.cn/UpFile/2010122214836668.pdf
[OSCCA-SM3]
  SM3 Cryptographic Hash Algorithm. December 2010. URL: http://www.oscca.gov.cn/UpFile/20101222141857786.pdf
[RFC2119]
  S. Bradner. Key words for use in RFCs to Indicate Requirement Levels. March 1997. Best Current Practice. URL: https://tools.ietf.org/html/rfc2119
[RFC3447]
  J. Jonsson; B. Kaliski. Public-Key Cryptography Standards (PKCS) #1: RSA Cryptography Specifications Version 2.1. February 2003. Informational. URL: https://tools.ietf.org/html/rfc3447
[RFC4055]
  J. Schaad; B. Kaliski; R. Housley. Additional Algorithms and Identifiers for RSA Cryptography for use in the Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile. June 2005. Proposed Standard. URL: https://tools.ietf.org/html/rfc4055
[RFC4056]
  J. Schaad. Use of the RSASSA-PSS Signature Algorithm in Cryptographic Message Syntax (CMS). June 2005. Proposed Standard. URL: https://tools.ietf.org/html/rfc4056
[RFC5480]
  S. Turner; D. Brown; K. Yiu; R. Housley; T. Polk. Elliptic Curve Cryptography Subject Public Key Information. March 2009. Proposed Standard. URL: https://tools.ietf.org/html/rfc5480
[SEC1]
  Standards for Efficient Cryptography Group (SECG), SEC1: Elliptic Curve Cryptography, Version 2.0, September 2000.

### A.2 Informative references

[ECDSA-ANSI]
  Public Key Cryptography for the Financial Services Industry: The Elliptic Curve Digital Signature Algorithm (ECDSA), ANSI X9.62-2005. American National Standards Institute, November 2005, URL: http://webstore.ansi.org/RecordDetail.aspx?sku=ANSI+X9.62%3A2005
[FIDOSecRef]
  R. Lindemann, D. Baghdasaryan, B. Hill, FIDO Security Reference. FIDO Alliance Proposed Standard. URLs:
  HTML: https://fidoalliance.org/specs/fido-u2f-v1.1-id-20160915/fido-security-ref-v1.1-id-20160915.html
  PDF: https://fidoalliance.org/specs/fido-u2f-v1.1-id-20160915/fido-security-ref-v1.1-id-20160915.pdf
[RFC3218]
  E. Rescorla. Preventing the Million Message Attack on Cryptographic Message Syntax. January 2002. Informational. URL: https://tools.ietf.org/html/rfc3218
[SecureElement]
  GlobalPlatform Card Specifications GlobalPlatform. Accessed March 2014. URL: https://www.globalplatform.org/specifications.asp
[TEE]
  GlobalPlatform Trusted Execution Environment Specifications GlobalPlatform. Accessed March 2014. URL: https://www.globalplatform.org/specifications.asp
[TEESecureDisplay]
  GlobalPlatform Trusted User Interface API Specifications GlobalPlatform. Accessed March 2014. URL: https://www.globalplatform.org/specifications.asp
[UAFASM]
  D. Baghdasaryan, J. Kemp, R. Lindemann, B. Hill, R. Sasson, FIDO UAF Authenticator-Specific Module API. FIDO Alliance Proposed Standard. URLs:
  HTML: fido-uaf-asm-api-v1.1-id-20150902.html
  PDF: fido-uaf-asm-api-v1.1-id-20150902.pdf
[UAFAppAPIAndTransport]
  B. Hill, D. Baghdasaryan, B. Blanke, FIDO UAF Application API and Transport Binding Specification. FIDO Alliance Proposed Standard. URLs:
  HTML: fido-uaf-client-api-transport-v1.1-id-20150902.html
  PDF: fido-uaf-client-api-transport-v1.1-id-20150902.pdf
[UAFAuthnrCommands]
  D. Baghdasaryan, J. Kemp, R. Lindemann, R. Sasson, B. Hill, FIDO UAF Authenticator Commands v1.0. FIDO Alliance Proposed Standard. URLs:
  HTML: fido-uaf-authnr-cmds-v1.1-id-20150902.html
  PDF: fido-uaf-authnr-cmds-v1.1-id-20150902.pdf
[UAFProtocol]
  R. Lindemann, D. Baghdasaryan, E. Tiffany, D. Balfanz, B. Hill, J. Hodges, FIDO UAF Protocol Specification v1.0. FIDO Alliance Proposed Standard. URLs:
  HTML: fido-uaf-protocol-v1.1-id-20150902.html
  PDF: fido-uaf-protocol-v1.1-id-20150902.pdf