Blowfish with maximum key length in OpenPGP

The Blowfish symmetric encryption algorithm allows keys with sizes ranging from 32 bits up to 448 bits.

We have received a question is it possible with our products to utilize the maximum key length of 448 bits. Unfortunately this is impossible because the OpenPGP standard (RFC 4880) has limited Blowfish keys to 128 bits.

The same applies to the other symmetric algorithms used in OpenPGP encryption.

A full list of the supported symmetric algorithms and key sizes can be found here:

https://tools.ietf.org/html/rfc4880#section-9.2