What encryption algorithm does the iOS keychain use to protect data?

Question

After extensive googling I haven\'t managed to find an answer to this question¹, which is surprising, since `security through obscurity\' isn\'t really security at al

Answer 1

According to this official Apple webpage :

Keychain items are encrypted using two different AES-256-GCM keys: a table key (metadata), and a per-row key (secret-key).

UPDATE: Update from May 2019. Encryption changed from 128 to 256.