[_8j50]

I must disagree with the "proprietary junk" assertion you made. While Your statement about AES is correct, Rijndael cipher of which AES is a subset can have bigger keys and block sizes. For marketing reasons they interchange Rijndael with AES since many have never heard of it.

[tgsovlerkhgsel]

While it is possible to do that, companies that understand what they're doing will generally stick to well-proven, standardized versions and companies that don't tend to also do other dangerous mistakes.

It's not a 100% guarantee that it's proprietary junk, but it's a very good indicator.