There are 5 ciphers and 1 scrap paper in Shadows of Evil.
Cipher #1[]
The cipher uses as key the reoccurring phrase "Only the cursed survive".
The plaintext is as follows:
"The elders will continue to seed space and time I must lead them to the place they cannot see"
Cipher #2[]
The cipher can be found by shooting down a picture in the Boxing Gym.
The plaintext is as follows:
"Although they have discovered the way Primis will fail"
Cipher #3[]
The cipher can be found by pressing the action button on a brick near the perk located in the Waterfront district.
The plaintext is as follows:
"M is interested in these worthless beings all his work will be undone"
Cipher #4[]
This cipher uses the Tupper's self-referential formula.
The plaintext is as follows:
"The formless one, will be their downfall"
Cipher #5[]
The plaintext is as follows:
"I am willing to do what must be done the plan must not fail"
Scrap Paper[]
There is a scrap paper around the map. The paper shows various drawings and notes from Edward Richtofen, detailing his knowledge of multiple universes and timelines. The drawing also shows four coordinates leading to four location which are visited in future Zombies maps: Lower Silesia, Hohenwerfen Castle, Pohnpei Island and Stalingrad.