Secrets are not encrypted by default in Kubernetes - Step-by-Step Execution

Process Flow - Secrets are not encrypted by default

Create Secret YAML

↓

kubectl apply Secret

↓

Secret stored in etcd

↓

Secret stored as base64 (not encrypted)

↓

Anyone with etcd access can decode Secret

↓

Enable Encryption at Rest to protect Secret

This flow shows how Kubernetes stores Secrets by default as base64 in etcd without encryption, exposing them unless encryption at rest is enabled.

Execution Sample

Kubernetes

apiVersion: v1
kind: Secret
metadata:
  name: mysecret
data:
  password: cGFzc3dvcmQ=

This YAML creates a Kubernetes Secret named 'mysecret' with a base64 encoded password.

Process Table

Step	Action	Data Stored in etcd	Security State
1	Create Secret YAML with password 'password'	password encoded as cGFzc3dvcmQ=	Secret is base64 encoded, not encrypted
2	Apply Secret with kubectl	Secret saved in etcd as base64 string	Secret still not encrypted
3	Access etcd storage directly	Retrieve base64 string cGFzc3dvcmQ=	Secret can be decoded easily
4	Decode base64 string	Decoded value: 'password'	Secret exposed in plain text
5	Enable Encryption at Rest in Kubernetes	Secret stored encrypted in etcd	Secret protected from direct etcd access

💡 By default, Secrets are stored base64 encoded but not encrypted, so enabling encryption at rest is needed for protection.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 5
Secret Data	none	password base64 encoded	stored base64 in etcd	retrieved base64 from etcd	stored encrypted in etcd

Key Moments - 3 Insights

Why is base64 encoding not the same as encryption?

Base64 encoding only changes the format to text; it does not hide the data. As shown in execution_table step 4, anyone can decode base64 to get the original secret.

What happens if someone accesses etcd directly without encryption enabled?

They can read Secrets easily because they are stored as base64 strings, which can be decoded to reveal the secret, as shown in execution_table step 3 and 4.

How does enabling Encryption at Rest change Secret storage?

Encryption at Rest stores Secrets encrypted in etcd, so even if someone accesses etcd, they cannot read the Secrets without the encryption keys, as shown in execution_table step 5.

Visual Quiz - 3 Questions

Look at the execution table, what is the format of the Secret stored in etcd after applying kubectl?

A Base64 encoded string

B Plain text

C Encrypted data

D Hashed value

💡 Hint

Check execution_table row 2 under 'Data Stored in etcd'

At which step does the Secret become readable in plain text?

A Step 2

B Step 3

C Step 4

D Step 5

💡 Hint

Look at execution_table where decoding happens

If Encryption at Rest is enabled, what changes in the Secret storage?

A Secrets are stored as base64 strings

B Secrets are stored encrypted in etcd

C Secrets are stored in plain text

D Secrets are deleted after use

💡 Hint

Refer to execution_table step 5 under 'Security State'

Concept Snapshot

Kubernetes Secrets are stored base64 encoded by default, not encrypted.
Base64 encoding only changes format, not security.
Anyone with etcd access can decode Secrets.
Enable Encryption at Rest to protect Secrets in etcd.
Encryption stores Secrets securely, preventing easy access.

Full Transcript

In Kubernetes, when you create a Secret, it is stored in etcd as a base64 encoded string, not encrypted. This means anyone who can access etcd can decode and read the Secret easily. The flow starts with creating a Secret YAML, applying it with kubectl, and storing it in etcd. Without encryption, the Secret is exposed. To protect Secrets, Kubernetes supports Encryption at Rest, which encrypts Secrets in etcd, making them safe from direct access. Base64 encoding is not encryption; it only changes the data format. Enabling Encryption at Rest is essential for securing sensitive data in Kubernetes.

Practice

1. What is the default way Kubernetes stores Secrets?

easy

A. Hashed using SHA-256 before storage

B. As base64 encoded plain text in etcd

C. Stored in an external vault automatically

D. Encrypted with AES-256 by default

Solution

1. Step 1: Understand Kubernetes default Secret storage

   Kubernetes stores Secrets in etcd as base64 encoded strings, which is not encryption but simple encoding.

2. Step 2: Confirm encryption is not enabled by default

   Encryption at rest must be explicitly configured; by default, Secrets are not encrypted.

3. Final Answer:

   As base64 encoded plain text in etcd -> Option B

4. Quick Check:

   Default Secret storage = base64 plain text [OK]

Hint: Remember: base64 is encoding, not encryption [OK]

Common Mistakes:

• Confusing base64 encoding with encryption
• Assuming Secrets are encrypted by default
• Thinking Kubernetes uses external vault automatically

2. Which of the following is the correct way to enable encryption of Secrets in Kubernetes?

easy

A. Configure EncryptionConfiguration file in API server flags

B. Set encryption: true in the Secret manifest

C. Add --encryption-provider flag to kubelet

D. Use kubectl encrypt secret command

Solution

1. Step 1: Identify where encryption is configured

   Encryption at rest is enabled by configuring the API server with an EncryptionConfiguration file and passing it via flags.

2. Step 2: Verify other options are invalid

   Kubelet does not handle encryption, Secret manifests do not have encryption fields, and kubectl has no encrypt command.

3. Final Answer:

   Configure EncryptionConfiguration file in API server flags -> Option A

4. Quick Check:

   Encryption enabled via API server config [OK]

Hint: Encryption config is on API server, not kubelet or kubectl [OK]

Common Mistakes:

• Trying to encrypt Secrets via kubectl commands
• Assuming kubelet manages encryption
• Adding encryption fields in Secret YAML

3. Given this snippet from an EncryptionConfiguration file:

{
  "kind": "EncryptionConfiguration",
  "apiVersion": "apiserver.config.k8s.io/v1",
  "resources": [
    {
      "resources": ["secrets"],
      "providers": [
        {"aescbc": {"keys": [{"name": "key1", "secret": "c2VjcmV0MTIzNDU2Nzg5MDEyMzQ1Njc4OTA="}]}},
        {"identity": {}}
      ]
    }
  ]
}

What does this configuration do?

medium

A. Encrypts Secrets using AES-CBC with key1, falling back to no encryption

B. Encrypts all resources except Secrets

C. Disables encryption for Secrets

D. Encrypts Secrets using identity provider only

Solution

1. Step 1: Analyze the providers list for Secrets

   The providers list has an AES-CBC encryption provider with a key named key1, followed by identity (no encryption) as fallback.

2. Step 2: Understand the effect on Secrets

   This means Secrets are encrypted with AES-CBC using key1; if decryption fails, identity provider returns plain data.

3. Final Answer:

   Encrypts Secrets using AES-CBC with key1, falling back to no encryption -> Option A

4. Quick Check:

   Encryption config with AES-CBC + identity fallback [OK]

Hint: First provider encrypts, second is fallback identity [OK]

Common Mistakes:

• Thinking identity means encryption is disabled
• Assuming all resources are encrypted, not just Secrets
• Confusing provider order effect

4. You configured encryption for Secrets but still see base64 encoded plain text in etcd. What is the most likely cause?

medium

A. Secrets manifest missing encryption annotation

B. Encryption key is too short

C. kubectl version is outdated

D. API server was not restarted after adding EncryptionConfiguration

Solution

1. Step 1: Check if API server reload is needed

   EncryptionConfiguration changes require API server restart to take effect.

2. Step 2: Verify other options are irrelevant

   Secrets do not need annotations for encryption, kubectl version does not affect encryption, and key length would cause errors, not silent failure.

3. Final Answer:

   API server was not restarted after adding EncryptionConfiguration -> Option D

4. Quick Check:

   API server restart required for encryption config [OK]

Hint: Restart API server after config changes [OK]

Common Mistakes:

• Forgetting to restart API server
• Adding encryption annotations to Secrets
• Blaming kubectl version for encryption issues

5. You want to ensure all Secrets in your cluster are encrypted at rest. Which steps should you follow? Select the correct sequence.

hard

A. Enable encryption in kube-proxy config, restart kube-proxy, check logs

B. Add encryption field to Secret manifests, restart kubelet, verify kubectl output

C. Create EncryptionConfiguration file, update API server flags, restart API server, verify etcd data

D. Run kubectl encrypt secrets, update RBAC, restart API server

Solution

1. Step 1: Prepare EncryptionConfiguration file

   Create a file defining encryption providers for Secrets, typically AES-CBC or AES-GCM.

2. Step 2: Update API server flags and restart

   Pass the EncryptionConfiguration file path to the API server via flags and restart it to apply changes.

3. Step 3: Verify Secrets are encrypted in etcd

   Check etcd data to confirm Secrets are stored encrypted, not just base64 encoded.

4. Final Answer:

   Create EncryptionConfiguration file, update API server flags, restart API server, verify etcd data -> Option C

5. Quick Check:

   Encryption setup = config file + API server restart + verify [OK]

Hint: Encryption needs config file + API server restart + verify [OK]

Common Mistakes:

• Trying to encrypt Secrets via manifest changes
• Restarting wrong components like kubelet or kube-proxy
• Using non-existent kubectl encrypt command