The current key used for email, package signing etc. is :
pub 4096R/CD3755FB 2015-09-19 [expires: 2025-09-16] Key fingerprint = 37DB 18EE 7668 BDA4 1D66 1DB7 B91A 917F CD37 55FB uid Georg Lutz <georg@georglutz.de> uid Georg Lutz <georg-com@georglutz.de> uid Georg Lutz <georg-list@georglutz.de> uid Georg Lutz <georglutz@gmx.de> sub 4096R/8CB9B8E9 2015-09-19 [expires: 2025-09-16]
Either fetch it from a public keyserver or download it here.