All Products
Search
Document Center

Key Management Service:Purchase and enable a KMS instance

Last Updated:Feb 04, 2026

A Key Management Service (KMS) instance provides key and secret management capabilities. You can use keys to encrypt and decrypt sensitive data and use secrets to avoid hardcoding credentials in your code. This topic describes how to purchase and enable a KMS instance.

Step 1: Purchase a KMS instance

  1. Log on to the KMS console. In the top navigation bar, select a region. In the navigation pane on the left, choose Resource > Instances.

  2. On the Instances page, click Create Instance, select a billing method, select the desired instance type, and then click Buy Now.

    Subscription

    Parameter

    Description

    Site

    The site where the instance's region is located. Options: International regions and Chinese mainland regions.

    Instance Type

    KMS provides default keys, including service keys and customer master keys, for cloud product encryption in each region. You do not need to purchase a KMS instance to use default keys, but the features are limited. Default keys are free to use. Only key rotation is a paid value-added service.

    Before purchasing a KMS instance, we recommend reading Product Selection to understand default keys and KMS instances.

    • Purchase a KMS instance

      A software key management instance is sufficient for most use cases. Select a hardware key management instance if your business requires physical-level security protection or needs to comply with strict regulations, such as those in the financial industry.

      • Software Key Management: Keys are stored in your dedicated database.

      • Hardware Key Management: Key generation, storage, encryption, and decryption rely on a dedicated hardware security module (HSM) that is compliant with Chinese Cryptographic Algorithm or FIPS 140-2 Level 3 certification. To purchase this type of instance, you must also purchase a Dedicated HSM. For more information, see Configure an HSM cluster for a KMS hardware key management instance.

    • Purchase value-added services for keys

      • Instance backup: Available only for software key management instances. After you enable a software key management instance, KMS automatically creates a free backup that stores data for 90 days. We recommend that you first evaluate the free backup service. If it does not meet your business requirements, you can purchase the instance backup service. For more information, see Backup management.

      • Default key rotation: Available only for the free default key.  For more information, see Default key rotation.

        Note

        If you purchase a KMS instance, the keys in the instance support rotation by default. You do not need to purchase this value-added service.

    Region

    We recommend selecting the same region as your business deployment. For more information, see Supported regions.

    Deployment Mode

    KMS instances support dual-zone and multi-zone configurations, offering high availability, disaster recovery, and load balancing.

    Note
    • Multi-zone deployments support up to three zones.

    • KMS instances in the Phillippines (Manila) and Thailand (Bangkok) regions support only single-zone deployment.

      For the number of zones in each region, see Regions and zones.

    Compute Performance

    The performance data of the KMS instance. For example, a value of 2,000 indicates a maximum performance of 2,000 QPS for symmetric cryptographic operations and 300 QPS for asymmetric cryptographic operations when they are processed independently.

    Note

    If you need a software key management instance with computing performance of 10,000 or 20,000, contact us.

    Number of Keys

    The key quota. The default value is 1,000.

    The quota is calculated based on the number of key versions, not the number of keys. For example, if a key has five versions, it consumes five from your key quota.

    Number of Secrets

    The secret quota. The default value is 0.

    The quota is calculated based on the number of secrets, regardless of the number of secret versions. A secret consumes only one from your secret quota, no matter how many versions it has.

    Note

    If you do not use secrets, skip this quota. You can add a secret quota later by upgrading the instance.

    Access Management Quantity

    This quota applies to two features:

    For example, to associate an instance with three VPCs and share it with two accounts, you need a quota of 5.

    The default value is 1. This allows the VPC attached to one KMS instance to access KMS resources.

    Log Analysis

    Specifies whether to enable log analysis. For more information, see Log Service.

    Warning

    You cannot disable log analysis after it is enabled. For information about the fees, see Product Billing.

    Log Storage Capacity

    The minimum capacity is 1,000 GB, and it increases in increments of 1,000 GB. To learn how to estimate the required capacity, see How to calculate the required log storage capacity.

    Quantity

    The number of KMS instances to purchase.

    Important

    Typically, you only need to purchase one KMS instance. To purchase multiple KMS instances, contact us.

    Duration

    Select the subscription duration as needed.

    Note

    You can select Auto-renewal on expiration. The KMS instance is automatically renewed after it expires.

    Pay-as-you-go

    Parameter

    Description

    Billing Method

    The fixed value is Pay-as-you-go 3.0.

    Instance Type

    A software key management instance is sufficient for most use cases. Select a hardware key management instance if your business requires physical-level security protection or needs to comply with strict regulations, such as those in the financial industry.

    • Software Key Management: Keys are stored in your dedicated database.

    • Hardware Key Management: Key generation, storage, and cryptographic operations rely on a dedicated Hardware Security Module (HSM) that is compliant with Chinese Cryptographic Algorithm or FIPS 140-2 Level 3 certification. To purchase this type of instance, you must also purchase a Dedicated HSM. For more information, see Configure an HSM cluster for a KMS hardware key management instance.

    Region

    We recommend selecting the same region as your business deployment. For more information, see Supported regions.

  3. Click Buy Now, read Terms of Service, and then click Pay to complete the purchase.

    After a successful purchase, wait 1 to 5 minutes for the new instance to appear on the Instances page.

Step 2: Enable the KMS instance

After you purchase a KMS instance, you must enable it before using key management and secret management.

Enable a software key management instance

Prerequisites

  • You have a VPC and a vSwitch.

    Before enabling the KMS instance, we recommend checking your existing VPCs, vSwitches, and their zones in the VPC console. You can also create a new VPC and vSwitch. For more information, see Create a VPC and a vSwitch or Create a vSwitch.

  • If you use an Alibaba Cloud account for the Alibaba Cloud China site (aliyun.com) to purchase a KMS instance in a region outside the Chinese mainland, or if you use an Alibaba Cloud account for the Alibaba Cloud international site (alibabacloud.com) to purchase a KMS instance in a region within the Chinese mainland, you must manually activate Alibaba Cloud DNS PrivateZone. For more information, see Enable PrivateZone.

    Note
    • If you use an Alibaba Cloud account for the Alibaba Cloud China site to purchase a KMS instance in a region within the Chinese mainland, or if you use an Alibaba Cloud account for the Alibaba Cloud international site to purchase a KMS instance in a region outside the Chinese mainland, Alibaba Cloud automatically activates PrivateZone for you.

    • KMS covers the domain resolution costs for the instance, so you do not incur fees from Alibaba Cloud DNS PrivateZone.

Procedure

  1. Log on to the KMS console. In the top navigation bar, select a region. In the navigation pane on the left, choose Resource > Instances.

  2. On the Software Key Management tab, find the target software key management instance and click Enable in the Actions column.

  3. In the Enable KMS Instance panel, complete the configurations and click Enable Now.

    Parameter

    Description

    Instance Name

    A custom name for the KMS instance. The name can contain letters, digits, and the following special characters: _/+=.@-.

    VPC ID

    Select a VPC to bind to the KMS instance.

    Zone Configuration

    This setting depends on the deployment mode selected during purchase. It supports dual-zone or multi-zone configurations. You can configure up to three zones in a multi-zone deployment.

    • Zone and vSwitch: Configure a zone and a vSwitch. Make sure that the vSwitch has at least one available IP address.

    • Other Zones: You can have zones randomly assigned or manually specify them.

    Note
    • Some regions provide only one zone. A KMS instance in these regions can be deployed only in a single zone.

    • The choice of zone has a negligible impact on latency and performance, so you can select zones based on your preference.

    Wait for about 30 minutes and then refresh the page. The software key management instance is enabled when its status changes to Enabled.

Enable a hardware key management instance

Prerequisites

  • You have configured an HSM cluster that the KMS instance can connect to. For more information, see Configure an HSM cluster for a KMS hardware key management instance.

    Warning

    If you need to add more HSMs to the cluster later, contact Alibaba Cloud technical support to set the cluster's synchronization method to automatic, which prevents synchronization failures.

  • A vSwitch is available in each zone that you configured for the KMS instance. A dual-zone deployment is used as an example.

    • (Recommended) Use the two vSwitches bound to the HSM instance: You do not need to create vSwitches. Just make sure that each vSwitch has at least four available IP addresses.

    • Do not use the two vSwitches bound to the HSM instance: You need to create two vSwitches in different zones. Each vSwitch must have at least four available IP addresses. For more information, see Create a vSwitch.

    You can log on to the VPC console, go to the vSwitches page, and click a target vSwitch to view the number of available IP addresses on its details page.

  • If you use an Alibaba Cloud account for the Alibaba Cloud China site (aliyun.com) to purchase a KMS instance in a region outside the Chinese mainland, or if you use an Alibaba Cloud account for the Alibaba Cloud international site (alibabacloud.com) to purchase a KMS instance in a region within the Chinese mainland, you must manually activate Alibaba Cloud DNS PrivateZone. For more information, see Enable PrivateZone.

    Note
    • If you use an Alibaba Cloud account for the Alibaba Cloud China site to purchase a KMS instance in a region within the Chinese mainland, or if you use an Alibaba Cloud account for the Alibaba Cloud international site to purchase a KMS instance in a region outside the Chinese mainland, Alibaba Cloud automatically activates PrivateZone for you.

    • KMS covers the domain resolution costs for the instance, so you do not incur fees from Alibaba Cloud DNS PrivateZone.

Procedure

  1. Log on to the KMS console. In the top navigation bar, select a region. In the navigation pane on the left, choose Resource > Instances.

  2. Click the Hardware Key Management tab, find the target hardware key management instance, and click Enable in the Actions column.

  3. In the Connect to HSM panel, configure the parameters, and then click Connect to HSM to specify an HSM cluster.

    Parameter

    Description

    Instance Name

    Enter a custom name for the KMS instance. The name can contain letters, digits, and the following special characters: _/+=.@-.

    Select Cluster

    Select the cluster that you configured in Cloud HSM.

    Note

    A hardware key management instance can be bound to only one HSM cluster.

    Configure HSM Access Secret.

    HSM cluster in the Chinese mainland

    The connection between a KMS hardware key management instance and an HSM uses mutual Transport Layer Security (TLS) authentication. When you purchase an HSM, you can choose to have certificates generated automatically. In this case, Cloud HSM automatically generates the certificates. You only need to configure the certificates on the client SDK side, and Cloud HSM will automatically deploy them on the server-side HSM. If you did not configure automatic certificate generation, you must configure a client certificate (a PKCS#12 certificate with a protection password) and a security domain certificate (the PEM-formatted CA certificate that issues the TLS server certificate for the HSM cluster). To generate certificates, see Configure bidirectional TLS authentication for a master HSM instance.

    • Client Protection Password: The protection password that you set when you generate the client certificate client.p12. If you used the certificate generation tool (hsm_certificate_generate), the default password is 12345678.

    • Client Certificate: A PKCS12 format certificate. Click Select File and select the generated client.p12 file to upload.

    • Security Domain Certificate: A CA certificate in PEM format. Click Select File and select the generated rootca.pem file to upload.

    HSM cluster outside the Chinese mainland

    • Username: The username of the HSM operator. This is a static field: kmsuser.

    • Password: The access password for the HSM operator. This is the password you set when you created the HSM operator.

    • Security Domain Certificate: A CA certificate in PEM format. Log on to the CloudHSM console, click the ID of any HSM instance in the cluster, and find ClusterOwnerCertificate at the bottom of the Instance Details tab. This is the security domain certificate. Copy the content directly or save it as a PEM file and then upload it.

    VPC

    This defaults to the VPC ID bound to the HSM and cannot be changed.

    Configure Zone and vSwitch

    This setting depends on the deployment mode selected during purchase. It supports dual-zone or multi-zone configurations. Each vSwitch in each zone must have at least four available IP addresses.

    For multi-zone deployment, you can configure up to three zones.

    Note

    The choice of zone has a negligible impact on latency and performance, so you can select zones based on your preference.

    Enablement takes about 30 minutes with a secret quota or 10 minutes without one. Refresh the page until the status changes to Enabled.

Enable an external key management instance

Prerequisites

  • You have purchased an external HSM and configured an XKI proxy. For more information, contact your HSM provider.

    Note

    For more information about the XKI Proxy server, see XKI Proxy Server.

  • KMS can connect to the XKI proxy over the Internet or via a VPC endpoint. To connect via a VPC endpoint, first create an endpoint service. For more information, see Create and manage endpoint services. Note the following points when you create the endpoint service:

    • The endpoint service's zones must match the zones selected for the KMS instance.

    • You must add your current Alibaba Cloud account to the whitelist of the endpoint service.

    • The Automatically Accept Endpoint Connections setting for the endpoint service must be set to Yes.

  • If you use an Alibaba Cloud account for the Alibaba Cloud China site (aliyun.com) to purchase a KMS instance in a region outside the Chinese mainland, or if you use an Alibaba Cloud account for the Alibaba Cloud international site (alibabacloud.com) to purchase a KMS instance in a region within the Chinese mainland, you must manually activate Alibaba Cloud DNS PrivateZone. For more information, see Enable PrivateZone.

    Note
    • If you use an Alibaba Cloud account for the Alibaba Cloud China site to purchase a KMS instance in a region within the Chinese mainland, or if you use an Alibaba Cloud account for the Alibaba Cloud international site to purchase a KMS instance in a region outside the Chinese mainland, Alibaba Cloud automatically activates PrivateZone for you.

    • KMS covers the domain resolution costs for the instance, so you do not incur fees from Alibaba Cloud DNS PrivateZone.

Procedure

  1. Log on to the KMS console. In the top navigation bar, select a region. In the navigation pane on the left, choose Resource > Instances.

  2. Click the External Key Management tab, find the target instance, and click Enable in the Actions column.

  3. In the Connect to HSM panel, configure the parameters, and then click Connect to HSM to specify an HSM cluster.

    Parameter

    Description

    Instance Name

    Enter a custom name for the KMS instance. The name can contain letters, digits, and the following special characters: _/+=.@-.

    VPC

    Select a VPC to bind to the KMS instance.

    Zone Configuration

    This setting depends on the deployment mode selected during purchase. It supports dual-zone or multi-zone configurations. You can configure up to three availability zones in a multi-zone deployment.

    • Zone and vSwitch: Configure a zone and a vSwitch. Make sure that the vSwitch has at least one available IP address.

    • Other Zones: You can have zones randomly assigned or manually specify them.

    Note
    • Some regions provide only one zone. A KMS instance in these regions can be deployed only in a single zone.

    • Dual-zone or multi-zone deployment is used to achieve high availability, disaster recovery, and load balancing for KMS. The difference is negligible in latency and performance between selecting a zone where your services are located and a zone where they are not. You can select a zone as needed.

    External Proxy Connectivity

    • Public Endpoint Connectivity: The KMS instance connects to the XKI proxy over the Internet.

    • VPC Endpoint Service Connectivity : The KMS instance connects to the XKI proxy using a VPC endpoint service.

    Domain Name of External Proxy

    This is required only when you set External Proxy Connectivity to Public Endpoint Connectivity. Enter the domain name of the XKI proxy.

    Endpoint Service

    This is required only when you set External Proxy Connectivity to VPC Endpoint Service Connectivity . Select an endpoint service.

    The zones selected for enabling the KMS instance must be the same as the zones of the endpoint service.

    External Proxy Configuration

    • Manual Configuration: Manually configure the External Proxy Path, Certificate Fingerprint, AccessKey ID, and AccessKey secret of the XKI proxy.

    • Configuration File Upload: Upload a file to configure the parameters.

    Enablement takes about 30 minutes with a secret quota or 10 minutes without one. Refresh the page until the status changes to Enabled.

FAQ

References