Version: 2026.04 | Last Updated: April 2026| Status: Draft

BYOK Setup Guide

Time Required: 30 minutes | Skill Level: Security Admin

This guide walks you through setting up Bring Your Own Key (BYOK) encryption with your AWS KMS Customer Managed Key (CMK).

Prerequisites

Before starting, ensure you have:

AWS Account with administrative access
AWS CLI installed and configured (aws configure)
ASCEND Platform admin account
ASCEND Enterprise subscription (BYOK is an enterprise feature)

Step 1: Create Your CMK in AWS KMS

Option A: AWS Console

Go to AWS Console → KMS → Customer managed keys
Click Create key
Select:
- Key type: Symmetric
- Key usage: Encrypt and decrypt
- Advanced options: KMS (key material origin)
Add alias: alias/ascend-byok-key
Add description: Customer managed key for ASCEND BYOK encryption
Complete the wizard (key administrators and users will be configured in Step 2)

Option B: AWS CLI

# Create the key
aws kms create-key \
  --description "Customer managed key for ASCEND BYOK encryption" \
  --key-usage ENCRYPT_DECRYPT \
  --origin AWS_KMS \
  --tags TagKey=Purpose,TagValue=ASCEND-BYOK

# Create an alias for easier reference
KEY_ID=$(aws kms list-keys --query 'Keys[-1].KeyId' --output text)
aws kms create-alias \
  --alias-name alias/ascend-byok-key \
  --target-key-id $KEY_ID

# Verify the key
aws kms describe-key --key-id alias/ascend-byok-key

Option C: Terraform

resource "aws_kms_key" "ascend_byok" {
  description             = "Customer managed key for ASCEND BYOK encryption"
  deletion_window_in_days = 30
  enable_key_rotation     = true

  tags = {
    Purpose = "ASCEND-BYOK"
    Environment = "production"
  }
}

resource "aws_kms_alias" "ascend_byok" {
  name          = "alias/ascend-byok-key"
  target_key_id = aws_kms_key.ascend_byok.key_id
}

Step 2: Configure Key Policy

Your CMK needs a key policy that grants ASCEND cross-account access.

Get ASCEND's AWS Account Information

Contact your ASCEND account representative or retrieve from the dashboard:

ASCEND AWS Account ID: <ASCEND_AWS_ACCOUNT_ID>
ASCEND IAM Role: arn:aws:iam::<ASCEND_AWS_ACCOUNT_ID>:role/ascend-byok-service

Update Key Policy

Add this statement to your key policy:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "Enable IAM policies",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::YOUR_ACCOUNT_ID:root"
      },
      "Action": "kms:*",
      "Resource": "*"
    },
    {
      "Sid": "Allow ASCEND to use this key for BYOK encryption",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::<ASCEND_AWS_ACCOUNT_ID>:role/ascend-byok-service"
      },
      "Action": [
        "kms:Encrypt",
        "kms:Decrypt",
        "kms:GenerateDataKey",
        "kms:GenerateDataKeyWithoutPlaintext",
        "kms:DescribeKey"
      ],
      "Resource": "*"
    }
  ]
}

Service-Specific Conditions

If your security policy requires restricting CMK usage to specific AWS services (e.g., kms:ViaService), consult your AWS architecture team before applying service-specific conditions. Incorrect conditions can prevent ASCEND from accessing the CMK, resulting in encryption failures.

Apply via AWS CLI

# Save policy to file
cat > key-policy.json << 'EOF'
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "Enable IAM policies",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::YOUR_ACCOUNT_ID:root"
      },
      "Action": "kms:*",
      "Resource": "*"
    },
    {
      "Sid": "Allow ASCEND to use this key",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::<ASCEND_AWS_ACCOUNT_ID>:role/ascend-byok-service"
      },
      "Action": [
        "kms:Encrypt",
        "kms:Decrypt",
        "kms:GenerateDataKey",
        "kms:GenerateDataKeyWithoutPlaintext",
        "kms:DescribeKey"
      ],
      "Resource": "*"
    }
  ]
}
EOF

# Apply the policy
aws kms put-key-policy \
  --key-id alias/ascend-byok-key \
  --policy-name default \
  --policy file://key-policy.json

Step 3: Verify Key Access

Before registering with ASCEND, verify the key is accessible:

# Test encryption
echo "test" | aws kms encrypt \
  --key-id alias/ascend-byok-key \
  --plaintext fileb:///dev/stdin \
  --output text --query CiphertextBlob | base64 --decode > /tmp/encrypted

# Test decryption
aws kms decrypt \
  --ciphertext-blob fileb:///tmp/encrypted \
  --output text --query Plaintext | base64 --decode

# Should output: test

Step 4: Get Your Key ARN

KEY_ARN=$(aws kms describe-key \
  --key-id alias/ascend-byok-key \
  --query 'KeyMetadata.Arn' \
  --output text)

echo "Your Key ARN: $KEY_ARN"

Save this ARN — you'll need it in the next step.

Step 5: Register Key with ASCEND

Using curl

# Get your ASCEND token
ASCEND_TOKEN="your-bearer-token"

# Register the key
curl -X POST https://pilot.owkai.app/api/v1/byok/keys \
  -H "Authorization: Bearer $ASCEND_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "cmk_arn": "arn:aws:kms:us-east-2:<YOUR_AWS_ACCOUNT_ID>:key/YOUR_KEY_ID",
    "cmk_alias": "ascend-byok-key"
  }'

Expected Response

{
  "status": "success",
  "message": "Customer managed key registered successfully",
  "key_id": "byok_abc123",
  "cmk_arn": "arn:aws:kms:us-east-2:<YOUR_AWS_ACCOUNT_ID>:key/YOUR_KEY_ID",
  "registration_time": "2026-04-02T10:30:00Z",
  "requires_waiver_acknowledgment": true
}

Step 6: Acknowledge Legal Waiver

BYOK requires acknowledgment of the legal waiver before activation.

View the Waiver

curl https://pilot.owkai.app/api/v1/byok/legal-waiver \
  -H "Authorization: Bearer $ASCEND_TOKEN"

Acknowledge the Waiver

curl -X POST https://pilot.owkai.app/api/v1/byok/legal-waiver/acknowledge \
  -H "Authorization: Bearer $ASCEND_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "acknowledge_data_loss_risk": true,
    "acknowledge_key_management_responsibility": true,
    "acknowledge_no_liability": true
  }'

Step 7: Verify BYOK is Active

Check Key Status

curl https://pilot.owkai.app/api/v1/byok/keys \
  -H "Authorization: Bearer $ASCEND_TOKEN"

Expected response:

{
  "status": "active",
  "cmk_arn": "arn:aws:kms:us-east-2:<YOUR_AWS_ACCOUNT_ID>:key/YOUR_KEY_ID",
  "cmk_alias": "ascend-byok-key",
  "registered_at": "2026-04-02T10:30:00Z",
  "waiver_acknowledged": true,
  "last_used": "2026-04-02T10:35:00Z"
}

Check Health

curl https://pilot.owkai.app/api/v1/byok/health \
  -H "Authorization: Bearer $ASCEND_TOKEN"

Expected response:

{
  "status": "healthy",
  "key_status": "active",
  "cmk_accessible": true,
  "last_encryption": "2026-04-02T10:35:00Z",
  "last_decryption": "2026-04-02T10:34:00Z"
}

Step 8: Enable Key Rotation (Recommended)

Enable automatic key rotation in AWS KMS:

aws kms enable-key-rotation --key-id alias/ascend-byok-key

# Verify rotation is enabled
aws kms get-key-rotation-status --key-id alias/ascend-byok-key

Step 9: Set Up CloudTrail Monitoring

Monitor all key usage in your AWS CloudTrail:

# Create CloudTrail for KMS events
aws cloudtrail create-trail \
  --name ascend-byok-audit \
  --s3-bucket-name your-cloudtrail-bucket \
  --include-global-service-events

# Enable KMS event logging
aws cloudtrail put-event-selectors \
  --trail-name ascend-byok-audit \
  --event-selectors '[{
    "ReadWriteType": "All",
    "IncludeManagementEvents": true,
    "DataResources": [{
      "Type": "AWS::KMS::Key",
      "Values": ["arn:aws:kms:us-east-1:YOUR_ACCOUNT:key/YOUR_KEY_ID"]
    }]
  }]'

Verification Checklist

After setup, verify:

CMK created in AWS KMS
Key policy grants ASCEND cross-account access
Key registered with ASCEND (/api/v1/byok/keys returns active)
Legal waiver acknowledged
Health check passes (/api/v1/byok/health returns healthy)
Key rotation enabled in AWS KMS
CloudTrail monitoring configured

What Happens Next

Once BYOK is active:

New data is encrypted with DEKs wrapped by your CMK
Existing data will be re-encrypted on next access (gradual migration)
All key operations are logged in both ASCEND and your CloudTrail
Key health is monitored continuously

Rollback Instructions

If you need to disable BYOK and return to ASCEND-managed encryption:

# Revoke BYOK key
curl -X DELETE https://pilot.owkai.app/api/v1/byok/keys \
  -H "Authorization: Bearer $ASCEND_TOKEN"

warning

Revoking BYOK will:

Migrate data back to ASCEND-managed encryption
Remove cross-account access to your CMK
Retain audit logs of the BYOK period

Next Steps

API Reference — Complete API documentation
Troubleshooting — Common issues and solutions
BYOK Overview — Return to overview

Support

For setup assistance:

Email: security@owkai.app
Enterprise Support: Contact your account representative

Prerequisites​

Step 1: Create Your CMK in AWS KMS​

Option A: AWS Console​

Option B: AWS CLI​

Option C: Terraform​

Step 2: Configure Key Policy​

Get ASCEND's AWS Account Information​

Update Key Policy​

Apply via AWS CLI​

Step 3: Verify Key Access​

Step 4: Get Your Key ARN​

Step 5: Register Key with ASCEND​

Using curl​

Expected Response​

Step 6: Acknowledge Legal Waiver​

View the Waiver​

Acknowledge the Waiver​

Step 7: Verify BYOK is Active​

Check Key Status​

Check Health​

Step 8: Enable Key Rotation (Recommended)​

Step 9: Set Up CloudTrail Monitoring​

Verification Checklist​

What Happens Next​

Rollback Instructions​

Next Steps​

Support​