I was curious as to the procedure for having an encryption key leaked and was hoping to have your opinions on how these two questions will be answered [if you were in the position]. Q1: Let's say, for instance, that you're making a social media network that stores private messages in a database network (such as Firebase) and uses basic encryption to store that data into an encrypted format (e.g., text message: "Hello Mous772!"; Firebase data: "deaErG5gao7J5qw/QI3EOA=="). But oh no! Someone got access to the encryption key used to encrypt hundreds of thousands of messages. You cannot simply delete thousands of messages because of this hacker, so how should you deal with this? This is where my question comes in. Is it possible to change the encryption key for all of the data if I am using the code system at the bottom of this question and using that code system to store encrypted data in Firebase? If so, how would you go about doing that? (Please use simple language; I'm not good with this stuff). Q2: What, in your opinion, is the best way to prevent this in the first place? I was told that a good solution was to store two sets of the same data; when one kegs it, we shut down the original and use the backup; however, this does not sound sustainable at all. I want to know what steps can be taken to ensure this never happens. [Please don't give me "Well... you can never *really hide these keys!" I'm well aware it's not possible to never have them leaked ever; I'm just looking for best practices only.] This is the encryption system we are using for this hypothetical app. // MARK: Value // MARK: Private private let key: Data private let iv: Data // MARK: - Initialzier init?(key: String, iv: String) { guard key.count == kCCKeySizeAES128 || key.count == kCCKeySizeAES256, let keyData = key.data(using: .utf8) else { debugPrint("Error: Failed to set a key.") return nil } guard iv.count == kCCBlockSizeAES128, let ivData = iv.data(using: .utf8) else { debugPrint("Error: Failed to set an initial vector.") return nil } self.key = keyData self.iv = ivData } // MARK: - Function // MARK: Public func encrypt(string: String) -> Data? { return crypt(data: string.data(using: .utf8), option: CCOperation(kCCEncrypt)) } func decrypt(data: Data?) -> String? { guard let decryptedData = crypt(data: data, option: CCOperation(kCCDecrypt)) else { return nil } return String(bytes: decryptedData, encoding: .utf8) } func crypt(data: Data?, option: CCOperation) -> Data? { guard let data = data else { return nil } let cryptLength = data.count + key.count var cryptData = Data(count: cryptLength) var bytesLength = Int(0) let status = cryptData.withUnsafeMutableBytes { cryptBytes in data.withUnsafeBytes { dataBytes in iv.withUnsafeBytes { ivBytes in key.withUnsafeBytes { keyBytes in CCCrypt(option, CCAlgorithm(kCCAlgorithmAES), CCOptions(kCCOptionPKCS7Padding), keyBytes.baseAddress, key.count, ivBytes.baseAddress, dataBytes.baseAddress, data.count, cryptBytes.baseAddress, cryptLength, &bytesLength) } } } } guard Int32(status) == Int32(kCCSuccess) else { debugPrint("Error: Failed to crypt data. Status \(status)") return nil } cryptData.removeSubrange(bytesLength..<cryptData.count) return cryptData } } //let password = "UserPassword1!" //let key128 = "1234567890123456" // 16 bytes for AES128 //let key256 = "12345678901234561234567890123456" // 32 bytes for AES256 //let iv = "abcdefghijklmnop" // 16 bytes for AES128 //let aes128 = AES(key: key128, iv: iv) //let aes256 = AES(key: key256, iv: iv) //let encryptedPassword128 = aes128?.encrypt(string: password) //aes128?.decrypt(data: encryptedPassword128) //let encryptedPassword256 = aes256?.encrypt(string: password) //aes256?.decrypt(data: encryptedPassword256)

Hello! I have been making an app where a user is able to create an account, as well as provide other important data like their name, address, weight, etc. When it comes to managing the data between view controllers, what do you recommend as a way to save the data for account creation purposes temporarily such as stage 1 (enter your username) and stage 2 (enter your password)(as moving into the next view controller through a segue removes all data?) As I am using firebase to process the data (not store it) I considered using user defaults with a temporary system where after 5 minutes, all data is wiped under a "session timeout", however I am skeptical of this. What are your thoughts as I am new to this?

I wanted to know, in the event that an issue arrises that needs to be addressed (such as a hack or privacy issue) does Apple have a button or process I can follow to temporarily suspend the app until you I choose to put it back up?

I have been working on an app, and am really happy with the designs on iPhones 15-11, however every time I use the iPhone SE, the designs look terrible and everything overlaps (yes even with restraints and stack views and what not.) I want to know could I make a seperate version of my app for every iPhone (that isn't the se) and a special dedicated version for SE users? If this isn't possible, can I just block SE users from the app?