Object-C是有反射（reflect）机制的，可以被用来做混淆，在一定程度上提高代码的安全性。
关键代码把核心逻辑尽量放在c层, 这样还有一个好处是iOS和android可以公用.
数据加密，服务器解析
一般对各个参数进行签名验证，对核心参数进行加密，而且防止别人进行重放攻击，一般都会将时间戳做为一个参数
Protection Techniques:
- Control flow obfuscation e.g. ARM instruction flows are mangled with redundant instructions to try to hide the original purpose of the code,
- Class and Method renaming - renames your methods and classes to meaningless names although you have to be careful where this is used as you can easily break your app because the Objective-C runtime is expecting to find certain names,
- String encryption - all static strings in the app are encrypted and code is inserted to decrypt the strings just before use in order to make static analysis harder
- Anti-debug - code is inserted to break the usual debuggers (not always successfully),
- Anti-tamper - usually builds a network of checksums that protect the binary code from modification,
- Objective-C runtime protection - usually checks obj-c registered method implementations to make sure that they are in the app and haven't been 'swizzled'.
- encrypt constant, strings, decrypt in real-time
- encrypt local stored files
Detection Techniques:
- detect debug status
- detect jail-break status
- integrity check of data or piece of code
Object-C code obfuscators:
- EnsureIT for Apple iOS
- Contaxiom Code Protection
- Arxan,
- Metaforic,
- Cryptanium
- iOS class-guard to rename class /method names
RE tools:
- class-dump
- gdb
- IDA pro/hopper disassembler
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