Man pages matching name crypt::authenc::gcm in section 3pm:

Crypt::AuthEnc::GCM.3pm.en	debian 10 / libcryptx-perl
Crypt::AuthEnc::GCM.3pm.en	debian 11 / libcryptx-perl
Crypt::AuthEnc::GCM.3pm.en	debian 12 / libcryptx-perl