# CfnKey Creates an AWS Payment Cryptography key, a logical representation of a cryptographic key, that is unique in your account and AWS Region . You use keys for cryptographic functions such as encryption and decryption. In addition to the key material used in cryptographic operations, an AWS Payment Cryptography key includes metadata such as the key ARN, key usage, key origin, creation date, description, and key state. When you create a key, you specify both immutable and mutable data about the key. The immutable data contains key attributes that define the scope and cryptographic operations that you can perform using the key, for example key class (example: `SYMMETRIC_KEY` ), key algorithm (example: `TDES_2KEY` ), key usage (example: `TR31_P0_PIN_ENCRYPTION_KEY` ) and key modes of use (example: `Encrypt` ). AWS Payment Cryptography binds key attributes to keys using key blocks when you store or export them. AWS Payment Cryptography stores the key contents wrapped and never stores or transmits them in the clear. For information about valid combinations of key attributes, see [Understanding key attributes](https://docs.aws.amazon.com/payment-cryptography/latest/userguide/keys-validattributes.html) in the *AWS Payment Cryptography User Guide* . The mutable data contained within a key includes usage timestamp and key deletion timestamp and can be modified after creation. You can use the `CreateKey` operation to generate an ECC (Elliptic Curve Cryptography) key pair used for establishing an ECDH (Elliptic Curve Diffie-Hellman) key agreement between two parties. In the ECDH key agreement process, both parties generate their own ECC key pair with key usage K3 and exchange the public keys. Each party then use their private key, the received public key from the other party, and the key derivation parameters including key derivation function, hash algorithm, derivation data, and key algorithm to derive a shared key. To maintain the single-use principle of cryptographic keys in payments, ECDH derived keys should not be used for multiple purposes, such as a `TR31_P0_PIN_ENCRYPTION_KEY` and `TR31_K1_KEY_BLOCK_PROTECTION_KEY` . When creating ECC key pairs in AWS Payment Cryptography you can optionally set the `DeriveKeyUsage` parameter, which defines the key usage bound to the symmetric key that will be derived using the ECC key pair. *Cross-account use* : This operation can't be used across different AWS accounts. *Related operations:* - [DeleteKey](https://docs.aws.amazon.com/payment-cryptography/latest/APIReference/API_DeleteKey.html) - [GetKey](https://docs.aws.amazon.com/payment-cryptography/latest/APIReference/API_GetKey.html) - [ListKeys](https://docs.aws.amazon.com/payment-cryptography/latest/APIReference/API_ListKeys.html) Extends: Construct › CfnElement › CfnRefElement › CfnResource › CfnKey Implements: IInspectable, ITaggableV2, IEnvironmentAware, IKeyRef, IConstruct, IDependable - CloudFormation: [`AWS::PaymentCryptography::Key`](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/aws-resource-paymentcryptography-key.html) - Source: Generated code - Type last changed: v2.260.0 · 16 Jun 2026 ## Example ```ts // The code below shows an example of how to instantiate this type. // The values are placeholders you should change. import { aws_paymentcryptography as paymentcryptography } from 'aws-cdk-lib'; const cfnKey = new paymentcryptography.CfnKey(this, 'MyCfnKey', { exportable: false, keyAttributes: { keyAlgorithm: 'keyAlgorithm', keyClass: 'keyClass', keyModesOfUse: { decrypt: false, deriveKey: false, encrypt: false, generate: false, noRestrictions: false, sign: false, unwrap: false, verify: false, wrap: false, }, keyUsage: 'keyUsage', }, // the properties below are optional deriveKeyUsage: 'deriveKeyUsage', enabled: false, keyCheckValueAlgorithm: 'keyCheckValueAlgorithm', policy: 'policy', replicationRegions: ['replicationRegions'], tags: [{ key: 'key', value: 'value', }], }); ``` ## Initializer ```ts new CfnKey(scope: Construct, id: string, props: CfnKeyProps) ``` ## Construct Props - `deriveKeyUsage`: string — The cryptographic usage of an ECDH derived key as defined in section A.5.2 of the TR-31 spec. - `enabled`: boolean | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) — Specifies whether the key is enabled. - `exportable`: boolean | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) (required) — Specifies whether the key is exportable. This data is immutable after the key is created. - `keyAttributes`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [CfnKey.KeyAttributesProperty](/cdk/api/v2/docs/aws-cdk-lib.aws_paymentcryptography.CfnKey.KeyAttributesProperty.html) (required) — The role of the key, the algorithm it supports, and the cryptographic operations allowed with the key. This data is immutable after the key is created. - `keyCheckValueAlgorithm`: string — The algorithm that AWS Payment Cryptography uses to calculate the key check value (KCV). It is used to validate the key integrity. For TDES keys, the KCV is computed by encrypting 8 bytes, each with value of zero, with the key to be checked and retaining the 3 highest order bytes of the encrypted result. For AES keys, the KCV is computed using a CMAC algorithm where the input data is 16 bytes of zero and retaining the 3 highest order bytes of the encrypted result. - `policy`: string — The resource-based policy attached to the key, in JSON format. - `replicationRegions`: string[] — The list of AWS Regions to remove from the key's replication configuration. The key will no longer be available for cryptographic operations in these regions after removal. Ensure no active operations depend on the key in these regions before removal. - `tags`: [CfnTag](/cdk/api/v2/docs/aws-cdk-lib.CfnTag.html)[] ## Properties - `attrKeyIdentifier`: string - `attrKeyOrigin`: string — The source of the key material. For keys created within AWS Payment Cryptography, the value is `AWS_PAYMENT_CRYPTOGRAPHY` . For keys imported into AWS Payment Cryptography, the value is `EXTERNAL` . - `attrKeyState`: string — The state of key that is being created or deleted. - `attrReplicationStatus`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) - `cdkTagManager`: [TagManager](/cdk/api/v2/docs/aws-cdk-lib.TagManager.html) — Tag Manager which manages the tags for this resource. - `CFN_RESOURCE_TYPE_NAME`: string (static) — The CloudFormation resource type name for this resource class. - `cfnOptions`: [ICfnResourceOptions](/cdk/api/v2/docs/aws-cdk-lib.ICfnResourceOptions.html) — Options for this resource, such as condition, update policy etc. - `cfnResourceType`: string — AWS resource type. - `creationStack`: string[] - `deriveKeyUsage`: string — The cryptographic usage of an ECDH derived key as defined in section A.5.2 of the TR-31 spec. - `enabled`: boolean | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) — Specifies whether the key is enabled. - `env`: [ResourceEnvironment](/cdk/api/v2/docs/aws-cdk-lib.interfaces.ResourceEnvironment.html) - `exportable`: boolean | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) — Specifies whether the key is exportable. - `keyAttributes`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [CfnKey.KeyAttributesProperty](/cdk/api/v2/docs/aws-cdk-lib.aws_paymentcryptography.CfnKey.KeyAttributesProperty.html) — The role of the key, the algorithm it supports, and the cryptographic operations allowed with the key. - `keyCheckValueAlgorithm`: string — The algorithm that AWS Payment Cryptography uses to calculate the key check value (KCV). - `keyRef`: [KeyReference](/cdk/api/v2/docs/aws-cdk-lib.interfaces.aws_paymentcryptography.KeyReference.html) — A reference to a Key resource. - `logicalId`: string — The logical ID for this CloudFormation stack element. The logical ID of the element is calculated from the path of the resource node in the construct tree. To override this value, use `overrideLogicalId(newLogicalId)`. - `node`: [Node](/cdk/api/v2/docs/constructs.Node.html) — The tree node. - `policy`: string — The resource-based policy attached to the key, in JSON format. - `ref`: string — Return a string that will be resolved to a CloudFormation `{ Ref }` for this element. If, by any chance, the intrinsic reference of a resource is not a string, you could coerce it to an IResolvable through `Lazy.any({ produce: resource.ref })`. - `replicationRegions`: string[] — The list of AWS Regions to remove from the key's replication configuration. - `stack`: [Stack](/cdk/api/v2/docs/aws-cdk-lib.Stack.html) — The stack in which this element is defined. CfnElements must be defined within a stack scope (directly or indirectly). - `tags`: [CfnTag](/cdk/api/v2/docs/aws-cdk-lib.CfnTag.html)[] ## Methods - `addDeletionOverride(path: string): void` — Syntactic sugar for `addOverride(path, undefined)`. **Parameters** - `path` — The path of the value to delete. - `addDependency(target: CfnResource): void` — Use `addResourceDependency` instead. This method has been renamed to `addResourceDependency` to more clearly set it apart from `construct.node.addDependency`. See the documentation of that function for more details. - `addDependsOn(target: CfnResource): void` — Use `addResourceDependency` instead. This can be used for resources across stacks (or nested stack) boundaries and the dependency will automatically be transferred to the relevant scope. This method has been renamed to `addResourceDependency`, which makes it more clear that this method operates at a different level from the construct-level `construct.node.addDependency()` mechanism. - `addMetadata(key: string, value: any): void` — Add a value to the CloudFormation Resource Metadata. - `addOverride(path: string, value: any): void` — Adds an override to the synthesized CloudFormation resource. To add a property override, either use `addPropertyOverride` or prefix `path` with "Properties." (i.e. `Properties.TopicName`). If the override is nested, separate each nested level using a dot (.) in the path parameter. If there is an array as part of the nesting, specify the index in the path. To include a literal `.` in the property name, prefix with a `\`. In most programming languages you will need to write this as `"\\."` because the `\` itself will need to be escaped. For example, ```typescript cfnResource.addOverride('Properties.GlobalSecondaryIndexes.0.Projection.NonKeyAttributes', ['myattribute']); cfnResource.addOverride('Properties.GlobalSecondaryIndexes.1.ProjectionType', 'INCLUDE'); ``` would add the overrides ```json "Properties": { "GlobalSecondaryIndexes": [ { "Projection": { "NonKeyAttributes": [ "myattribute" ] ... } ... }, { "ProjectionType": "INCLUDE" ... }, ] ... } ``` The `value` argument to `addOverride` will not be processed or translated in any way. Pass raw JSON values in here with the correct capitalization for CloudFormation. If you pass CDK classes or structs, they will be rendered with lowercased key names, and CloudFormation will reject the template. **Parameters** - `path` — - The path of the property, you can use dot notation to override values in complex types. - `value` — - The value. - `addPropertyDeletionOverride(propertyPath: string): void` — Adds an override that deletes the value of a property from the resource definition. **Parameters** - `propertyPath` — The path to the property. - `addPropertyOverride(propertyPath: string, value: any): void` — Adds an override to a resource property. Syntactic sugar for `addOverride("Properties.<...>", value)`. **Parameters** - `propertyPath` — The path of the property. - `value` — The value. - `addResourceDependency(target: CfnResource, reason?: string): void` — Indicates that this resource depends on another resource and cannot be provisioned unless the other resource has been successfully provisioned. This can be used for resources across stacks (or nested stack) boundaries and the dependency will automatically be transferred to the relevant scope. This method only adds dependencies between L1 resources. If you are looking for a generic construct-to-construct dependency mechanism that works for all constructs including L2s, use `construct.node.addDependency` instead. - `applyCrossStackReferenceStrength(strength: ReferenceStrength): void` — Sets the cross-stack reference strength for this resource. When set, any cross-stack reference to this resource will use the specified strength instead of the global default from the consuming stack's context. **Parameters** - `strength` — - The reference strength to use for this resource. - `applyRemovalPolicy(policy?: RemovalPolicy, options?: RemovalPolicyOptions): void` — Sets the deletion policy of the resource based on the removal policy specified. The Removal Policy controls what happens to this resource when it stops being managed by CloudFormation, either because you've removed it from the CDK application or because you've made a change that requires the resource to be replaced. The resource can be deleted (`RemovalPolicy.DESTROY`), or left in your AWS account for data recovery and cleanup later (`RemovalPolicy.RETAIN`). In some cases, a snapshot can be taken of the resource prior to deletion (`RemovalPolicy.SNAPSHOT`). A list of resources that support this policy can be found in the following link: - `cfnPropertyName(cdkPropertyName: string): string` - `getAtt(attributeName: string, typeHint?: ResolutionTypeHint): Reference` — Returns a token for an runtime attribute of this resource. Ideally, use generated attribute accessors (e.g. `resource.arn`), but this can be used for future compatibility in case there is no generated attribute. **Parameters** - `attributeName` — The name of the attribute. - `getMetadata(key: string): any` — Retrieve a value value from the CloudFormation Resource Metadata. - `inspect(inspector: TreeInspector): void` — Examines the CloudFormation resource and discloses attributes. **Parameters** - `inspector` — tree inspector to collect and process attributes. - `isCfnElement(x: any): boolean` (static) — Returns `true` if a construct is a stack element (i.e. part of the synthesized cloudformation template). Uses duck-typing instead of `instanceof` to allow stack elements from different versions of this library to be included in the same stack. **Returns:** The construct as a stack element or undefined if it is not a stack element. - `isCfnKey(x: any): boolean` (static) — Checks whether the given object is a CfnKey. - `isCfnResource(x: any): boolean` (static) — Check whether the given object is a CfnResource. - `isConstruct(x: any): boolean` (static) — Checks if `x` is a construct. Use this method instead of `instanceof` to properly detect `Construct` instances, even when the construct library is symlinked. Explanation: in JavaScript, multiple copies of the `constructs` library on disk are seen as independent, completely different libraries. As a consequence, the class `Construct` in each copy of the `constructs` library is seen as a different class, and an instance of one class will not test as `instanceof` the other class. `npm install` will not create installations like this, but users may manually symlink construct libraries together or use a monorepo tool: in those cases, multiple copies of the `constructs` library can be accidentally installed, and `instanceof` will behave unpredictably. It is safest to avoid using `instanceof`, and using this type-testing method instead. **Parameters** - `x` — Any object. **Returns:** true if `x` is an object created from a class which extends `Construct`. - `obtainDependencies(): Stack | CfnResource[]` — Retrieves an array of resources and stacks this resource depends on. For resources depended on directly, returns the `CfnResource` object. For dependencies on other stacks, returns the `Stack` object. The order of the array is not guaranteed. - `overrideLogicalId(newLogicalId: string): void` — Overrides the auto-generated logical ID with a specific ID. **Parameters** - `newLogicalId` — The new logical ID to use for this stack element. - `removeDependency(target: CfnResource): void` — Use `removeResourceDependency` instead This can be used for resources across stacks (including nested stacks) and the dependency will automatically be removed from the relevant scope. - `removeResourceDependency(target: CfnResource): void` — Indicates that this resource no longer depends on another resource. This can be used for resources across stacks (including nested stacks) and the dependency will automatically be removed from the relevant scope. - `replaceDependency(target: CfnResource, newTarget: CfnResource): void` — Replaces one dependency with another. **Parameters** - `target` — The dependency to replace. - `newTarget` — The new dependency to add. - `toString(): string` — Returns a string representation of this construct. **Returns:** a string representation of this resource - `with(...mixins: IMixin[]): IConstruct` — Applies one or more mixins to this construct. Mixins are applied in order. The list of constructs is captured at the start of the call, so constructs added by a mixin will not be visited. Use multiple `with()` calls if subsequent mixins should apply to added constructs.