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Security Architecture and Engineering

After confirming an application is vulnerable to a padding-oracle attack, the development team wants a fix that removes the vulnerability rather than just slowing the attacker down. Which change most directly closes the padding oracle?

• AAdd a short random delay before returning any decryption error, to make timing analysis harder
• BSwitch to an authenticated encryption mode that verifies integrity first
• CLog every failed decryption attempt for later review by the security team
• DIncrease the encryption key length used by the current mode