Inside Keychain & Secure Enclave: Where Your Secrets Really Live

On paper, iOS is “secure by default.” In practice, real apps still leak secrets, reuse keys, and leave long-lived tokens lying around like lost house keys under the doormat.

In this episode, we go deep into where your app's secrets actually live on iOS — and what it really means to “use Keychain” or “leverage the Secure Enclave” in a way that would make a red teamer sweat.

This episode: Where your secrets really live

If you build or ship iOS apps, you're sitting on a pile of secrets:

• API keys and client secrets
• OAuth tokens and refresh tokens
• Private keys for signing or encryption
• Session cookies and device bindings
• Crypto seeds, recovery phrases, and more

In this episode, we break down:

• What actually counts as a secret in a modern iOS app
• What the iOS Keychain is (and what it isn't)
• How the Secure Enclave fits into the picture
• Where things go wrong in real production apps
• Concrete ways to upgrade how you store and rotate secrets

You'll come away with a mental model you can explain to your team — not just “the OS encrypts it somehow.”

Keychain 101 (for people who already skimmed the docs)

Most people think of the Keychain as a magic encrypted dictionary.

In reality, it's:

• A structured database per device, per user
• Backed by hardware-backed encryption where possible
• Controlled by entitlements, access groups, and accessibility classes

We talk about how this actually plays out:

• Why kSecAttrAccessibleAfterFirstUnlock can be both convenient and risky
• How Keychain access groups affect what your different apps and extensions can see
• What happens to Keychain items across backups, restores, and device changes

You'll hear real-world examples where the right Keychain flags mattered more than any fancy crypto primitive.

Secure Enclave: more than a buzzword

“Uses the Secure Enclave” sounds impressive in a slide deck.

We unpack what that really means:

• What the Secure Enclave actually is (and what runs on it)
• The difference between keys stored in the Secure Enclave vs. keys merely protected by it
• When you should reach for Secure Enclave–backed keys versus “just Keychain”
• Why UX and key lifecycle often end up being the real constraints

We also talk about the kinds of attacks the Secure Enclave is meant to resist — and what it definitely doesn't save you from.

Common failure modes we see in the wild

Most production problems aren't exotic. They're boring, repeatable patterns:

• Long-lived tokens with permissive accessibility
  Tokens stored with accessibility settings that expose them when the device is locked
• No rotation plan
  Secrets that never rotate because “it's hard to migrate existing users”
• Misconfigured access groups
  Multiple apps or extensions unexpectedly sharing secrets
• Backup/restore confusion
  Orphaned secrets or stuck users after device changes
• UserDefaults or file storage for sensitive data
  “Temporary” storage that quietly becomes permanent

We walk through how these missteps turn into real account takeover and data-exfiltration paths — and how attackers chain them with phishing or device theft.

Three things you can do this week

If you only do a small amount of work after this episode, make it count. Here are three concrete things you can do with your team this week:

Small, deliberate improvements to how you store, classify, and rotate secrets are often worth more than another “advanced” crypto feature.