List of Used Keys

The following keys are used in the PowerAuth cryptography scheme.

name	created as	purpose
key_master *
`KEY_MASTER_P256_PRIVATE`	ECDSA/ECDH - private key	Stored on server, for backward compatibility with cryptography version 3 clients, used to assure authenticity of data while transferring from server to client during application scoped use-cases (i.e., device activation).
`KEY_MASTER_P256_PUBLIC`	ECDSA/ECDH - public key	Stored on client, for backward compatibility with cryptography version 3 clients, used to verify authenticity of data while transferring from server to client during application scoped use-cases (i.e., device activation).
`KEY_MASTER_ECDSA_P384_PRIVATE`	ECDSA - private key	Stored on server, used to assure authenticity of `KEY_SERVER_*_PUBLIC` while transferring from server to client
`KEY_MASTER_ECDSA_P384_PUBLIC`	ECDSA - public key	Stored on client, used to verify authenticity of data while transferring from server to client.
`KEY_MASTER_MLDSA65_PRIVATE`	ML-DSA - private key	Stored on server, used to assure authenticity of `KEY_SERVER_*_PUBLIC` while transferring from server to client
`KEY_MASTER_MLDSA65_PUBLIC`	ML-DSA - public key	Stored on client, used to verify authenticity of data while transferring from server to client.
`KEY_MASTER_MLDSA87_PRIVATE`	ML-DSA - private key	Stored on server, used to assure authenticity of `KEY_SERVER_*_PUBLIC` while transferring from server to client
`KEY_MASTER_MLDSA87_PUBLIC`	ML-DSA - public key	Stored on client, used to verify authenticity of data while transferring from server to client.
key_device*_
`KEY_DEVICE_P256_PRIVATE`	ECDH/ECDSA - private key	Stored on client, for backward compatibility with cryptography version 3 clients, used to assure authenticity of data signed by the user
`KEY_DEVICE_P256_PUBLIC`	ECDH/ECDSA - public key	Stored on server, for backward compatibility with cryptography version 3 clients, used to assure authenticity of data signed by the user
`KEY_DEVICE_ECDSA_P384_PRIVATE`	ECDSA - private key	Stored on client, used to assure authenticity of data signed by the user
`KEY_DEVICE_ECDSA_P384_PUBLIC`	ECDSA - public key	Stored on server, used to verify authenticity of data signed by the user
`KEY_DEVICE_MLDSA65_PRIVATE`	ML-DSA - private key	Stored on client, used to assure authenticity of data signed by the user
`KEY_DEVICE_MLDSA65_PUBLIC`	ML-DSA - public key	Stored on server, used to verify authenticity of data signed by the user
`KEY_DEVICE_MLDSA87_PRIVATE`	ML-DSA - private key	Stored on client, used to assure authenticity of data signed by the user
`KEY_DEVICE_MLDSA87_PUBLIC`	ML-DSA - public key	Stored on server, used to verify authenticity of data signed by the user
key_server *
`KEY_SERVER_P256_PRIVATE`	ECDH/ECDSA - private key	Stored on server, for compatibility with version 3 clients, used to assure authenticity of data signed by the user
`KEY_SERVER_P256_PUBLIC`	ECDH/ECDSA - public key	Stored on client, for compatibility with version 3 clients, used to assure authenticity of data signed by the user
`KEY_SERVER_ECDSA_P384_PRIVATE`	ECDSA - private key	Stored on server, used to assure authenticity of data signed by the user
`KEY_SERVER_ECDSA_P384_PUBLIC`	ECDSA - public key	Stored on client, used to verify authenticity of data signed by the user
`KEY_SERVER_MLDSA65_PRIVATE`	ML-DSA - private key	Stored on server, used to assure authenticity of data signed by the user
`KEY_SERVER_MLDSA65_PUBLIC`	ML-DSA - public key	Stored on client, used to verify authenticity of data signed by the user
`KEY_SERVER_MLDSA87_PRIVATE`	ML-DSA - private key	Stored on server, used to assure authenticity of data signed by the user
`KEY_SERVER_MLDSA87_PUBLIC`	ML-DSA - public key	Stored on client, used to verify authenticity of data signed by the user
other
`KEY_TEMPORARY_SECRET`	ECDH/Hybrid shared secret	A key deduced using `SharedSecret` protocol at the requested level of security. This is a temporary shared secret for E2EE purposes
`KEY_ACTIVATION_SECRET`	ECDH/Hybrid shared secret	A key deduced using `SharedSecret` protocol at the requested level of security. This is a long term shared secret created between the client and the server.
`KEY_AUTHENTICATION_CODE_POSSESSION`	KDF derived key from `KDK_AUTHENTICATION_CODE`	A signing key associated with the possession factor.
`KEY_AUTHENTICATION_CODE_KNOWLEDGE`	KDF derived key from `KDK_AUTHENTICATION_CODE`	A key associated with the knowledge factor.
`KEY_AUTHENTICATION_CODE_BIOMETRY`	KDF derived key from `KDK_AUTHENTICATION_CODE`	A key associated with the biometry factor.
`KEK_AUTHENTICATION_CODE_POSSESSION`	Key derived from unique device’s data	Encrypts and decrypts `KEY_AUTHENTICATION_CODE_POSSESSION` on the client.
`KEK_AUTHENTICATION_CODE_KNOWLEDGE`	Derived from user’s password or PIN	Encrypts and decrypts `KEY_AUTHENTICATION_CODE_KNOWLEDGE` on the client.
`KEK_AUTHENTICATION_CODE_BIOMETRY`	Platform specific	Encrypts and decrypts `KEY_AUTHENTICATION_CODE_BIOMETRY` on the client.

Label registry

The following table contains the list of all derivation labels for KDF function used in the protocol.

Label	Derived key	Source key	Description
Authentication Codes
`auth`	KDK_AUTHENTICATION_CODE	KEY_ACTIVATION_SECRET	Base for PowerAuth authentication code purpose
`auth/possession`	KEY_AUTHENTICATION_CODE_POSSESSION	KDK_AUTHENTICATION_CODE	Possession factor
`auth/knowledge`	KEY_AUTHENTICATION_CODE_KNOWLEDGE	KDK_AUTHENTICATION_CODE	Initial knowledge factor, before password is changed
`auth/biometry`	KEY_AUTHENTICATION_CODE_BIOMETRY	KDK_AUTHENTICATION_CODE	Initial biometry factor, if biometry is enabled in activation process
Shared Secret
`shared-secret/ec-p384`	KEY_SHARED_SECRET³	ECDH	Shared secret calculated with EC_P384 algorithm
`shared-secret/ec-p384-ml-l3`	KEY_SHARED_SECRET³	ECDH+ML-KEM	Shared secret calculated with EC_P384_ML_L3 algorithm
`shared-secret/ec-p384-ml-l5`	KEY_SHARED_SECRET³	ECDH+ML-KEM	Shared secret calculated with EC_P384_ML_L5 algorithm
Encryption
`enc`	KDK_ENCRYPTION	KEY_ACTIVATION_SECRET	Base for encryption purpose
`aead/enc`	KEY_ENC	BASE_KEY¹	AEAD key for encryption
`aead/mac`	KEY_MAC	BASE_KEY¹	AEAD key for authentication
`enc/local`	KEY_LOCAL_DATA	DEVICE_KEY²	Key that encrypts local data that suppose to be always available
`enc/kek-possession`	KEK_AUTHENTICATION_CODE_POSSESSION	DEVICE_KEY²	Key that encrypts KEY_AUTHENTICATION_CODE_POSSESSION
Vault
`vault`	KDK_VAULT	KEY_ACTIVATION_SECRET	Base for local vault encryption
`vault/kek-device-private`	KEK_DEVICE_PRIVATE	KDK_VAULT	Key that encrypts KEY_DEVICE_PRIVATE
`vault/kdk-app-vault-knowledge`	KDK_APP_VAULT_KNOWLEDGE	KDK_VAULT	KDK for application specific purposes, provided only after 2FA knowledge authentication
`vault/kdk-app-vault-2fa`	KDK_APP_VAULT_2FA	KDK_VAULT	KDK for application specific purposes, provided only after any 2FA authentication
Utility
`util`	KDK_UTILITY	KEY_ACTIVATION_SECRET	KDK for other purposes, always available
`util/mac/ctr-data`	KEY_MAC_CTR_DATA	KDK_UTILITY	Compute MAC from hash based counter
`util/mac/status`	KEY_MAC_STATUS	KDK_UTILITY	Compute MAC from activation status data
`util/mac/get-app-temp-key`	KEY_MAC_GET_APP_TEMP_KEY	APP_SECRET	Key for signing payload in getting temporary key request in application scope (APP_SECRET is decoded from Base64 constant)
`util/mac/get-act-temp-key`	KEY_MAC_GET_ACT_TEMP_KEY	KDK_UTILITY	Key for signing payload in getting temporary key request in activation scope
`util/mac/personalized-data`	KEY_MAC_PERSONALIZED_DATA	KDK_UTILITY	Compute MAC for personalized data, typically displayed as QR code
`util/key-e2ee-sh2`	KEY_E2EE_SHARED_INFO2	KDK_UTILITY	Key for SHARED_INFO_2 calculation for E2EE
`util/app`	KDK_APP_UTILITY	KDK_UTILITY	KDK for application specific purposes
Other
`other/expand-biometry-key`	KEK_AUTHENTICATION_CODE_BIOMETRY	128-bit KEK_AUTHENTICATION_CODE_BIOMETRY	Expands 128 bit biometry factor related KEK to 256 bit

Notes

Note 1: In E2EE, BASE_KEY is equal to KEY_TEMPORARY_SHARED_SECRET.

Note 2: DEVICE_KEY is calculated as Hash.sha3_256("device-specific-data")

Note 3: KEY_SHARED_SECRET is KEY_ACTIVATION_SECRET or KEY_TEMPORARY_SHARED_SECRET, depending on purpose of established secret.

Example

The following example shows how to calculate the derived key. Let’s say we want to get the value for KEY_MAC_STATUS:

SecretKey KDK_UTILITY    = KDF.derive(KEY_ACTIVATION_SECRET, "util");
SecretKey KEY_MAC_STATUS = KDF.derive(KDK_UTILITY, "util/mac/status");

Last updated on Feb 19, 2026 (10:25) Edit on Github Send Feedback