[ctz]

The other base64 prefix to look out for is `MI`. `MI` is common to every ASN.1 DER encoded object (all public and private keys in standard encodings, all certificates, all CRLs) because overwhelmingly every object is a `SEQUENCE` (0x30 tag byte) followed by a length introducer (top nibble 0x8). `MII` is very very common, because it introduces a `SEQUENCE` with a two byte length.

[schoen]

You'll also see "AQAB" a lot. This is the base64 version of the integer representation of 65537, the usual public exponent parameter e in modern RSA implementations.

[Muromec]

I for one wait for the day when quantum computers will break all the encryption forever so nobody will have to suffer broken asn1 decoders, plaintext specifications of machine-readable formats and unearned aura of arcane art that surrounds the whole thing.

[ctz]

asn1 enjoyers can also look forward to the sweet release of death. though if you end up in hell you might end up staring at XER for the rest of eternity