請 ChatGPT 用 Swift 做符合 PCI DSS 的信用卡號碼加密

在網路上雖然有找到一些做法，不過還是丟丟看 ChatGPT 請他幫忙回答看看。

回答內容有助解和說明還滿好懂的就留一下了。

問題

Please implement credit card number encryption that fits PCIDSS requirement in Swift

回答

PCI DSS (Payment Card Industry Data Security Standard) is a set of security requirements for organizations that handle credit card information. These requirements are designed to protect credit card data from being accessed or stolen by unauthorized parties.

To encrypt credit card numbers in a way that meets the requirements of PCI DSS, you can use the AES (Advanced Encryption Standard) encryption algorithm in GCM (Galois/Counter Mode). This provides both confidentiality (the encrypted data cannot be read by unauthorized parties) and integrity (the encrypted data cannot be modified without being detected) for the credit card numbers.

Here is an example of how you might implement credit card number encryption in Swift using AES-GCM:

import CryptoKit

// Generate a symmetric key to use for encrypting the credit card number.
let key = SymmetricKey(size: .bits256)

// Convert the credit card number to a string of bytes.
let creditCardNumberBytes = [UInt8]("1234 5678 9012 3456".utf8)

// Encrypt the credit card number using the symmetric key.
let sealedBox = try! AES.GCM.seal(creditCardNumberBytes, using: key)

// Convert the sealed box to a base64-encoded string.
let encryptedCreditCardNumber = sealedBox.combined!.base64EncodedString()

In this example, the symmetric key is generated using a key size of 256 bits, which is the recommended size for AES-GCM according to PCI DSS. The credit card number is converted to a string of bytes and then encrypted using the AES.GCM.seal method. The resulting sealed box is then converted to a base64-encoded string, which can be stored or transmitted securely.

To decrypt the encrypted credit card number, you can use the following code:

// Convert the encrypted credit card number from a base64-encoded string to a sealed box.
let sealedBox = try! AES.GCM.SealedBox(combined: Data(base64Encoded: encryptedCreditCardNumber))

// Decrypt the credit card number using the symmetric key.
let creditCardNumberBytes = try! AES.GCM.open(sealedBox, using: key)

// Convert the decrypted credit card number from bytes to a string.
let creditCardNumber = String(bytes: creditCardNumberBytes, encoding: .utf8)!

I hope this helps. Let me know if you have any other questions.