I was dealing with a good old anti-tampering userspace library last week. They did everything right.

The process detects that it's traced (by asking the kernel nicely) and shuts down. So I patched the kernel and now I can connect with and poke around gdb.

I can't put a software breakpoint because the process computes checksum of it's memory and jumps through a table index computed from a hash, so I had to put the hardware read watchpoint on modified memory location, record who reads it and patch the jump index to the right one.

Of course, there is another function that checksums the memory and runs the process into sigsegv, it has tons of obfuscated confusing stuff, so I have to patch it with 'lol return 0'.

And then I can finally use frida to disable ssl pinning to mitmproxy it. It all took a week to bypass all the levels of obfuscation, find the actual thing I was looking for and extract it. Can't imagine how much time the people at $securitycompanyname spent on adding all those levels of obfuscation and anti-debug. More than a week for sure. What was it doing? A custom HOTP.

It wasn't any better on actual secure boots 20 years ago where bootloader checksummed the whole firmware before transferring control, because bootloader itself was in ROM and of course it had subtle logical bugs and you only need to find one and bootloader is there in ROM bugged forever.

How many more amateur attempts did these layers thwart? Did its creators collect enough revenue before the crack was produced?

I suppose uncrackable software, in the sense of e.g. license protection, cannot exist. Software is completely beholden to hardware, and known hardware can be arbitrarily emulated, and there's nowhere to hide any tamper-resistant secret bits. Only in a combination with locked-down, uncrackable hardware can properly designed software without critical bugs remain uncrackable; see stuff like yubikeys. Similarly, communication can remain uncrackable as long as the secret bits (like a private key) remain secret.

How was your experience with Xbox? I heard it was rather watertight?