Here is the list of all Remnant Decryption Puzzles and their solutions. In total there are 22 Remnant decryption puzzles, some of them (6 puzzles) are missable! You need to solve 20 puzzles to get Cryptographer achievement.
Achievement: Cryptographer
Complete 20 Remnant puzzles in a single playthrough.
Eos: 4 puzzles (1 missable)
Havarl: 3 puzzles (1 missable)
Voeld: 6 puzzles (1 missable)
Kadara: 2 puzzles (1 missable)
Elaaden: 5 puzzles (1 missable)
H-047c: 1 puzzle
Meridian / Khi Tasira: 1 puzzle (1 missable)
The puzzle blocks access to one of the Remnant monoliths located on the planet Eos. Solving the puzzle is necessary to complete A Better Beginning mission.
Missable! The puzzle blocks access to the "bonus" container located inside the vault. You visit this vault during A Better Beginning mission.
The puzzle blocks access to the hidden cache which you can find inside the additional vault located in in the southeastern part of Eos. You visit this vault during Task: The Ghost of Promise mission.
The puzzle blocks access to the hidden cache which you can find inside the additional vault located in in the northwestern part of Eos. You visit this vault during Task: Data Trail mission.
The puzzle blocks access to the Remnant monolith located on the planet Havarl. Solving the puzzle is necessary to complete Helping Havarl's Scientists mission.
Missable! The puzzle blocks access to the "bonus" skill up console (+2 Skill Points) located inside the vault. You visit this vault during A Dying Planet mission.
The puzzle blocks access to one of the Remnant consoles which allow you to reach hidden container with fusion mod inside.
The puzzles blocks access to three Remnant monoliths located on the planet Voeld. Solving the puzzles is necessary to complete Restoring a World mission.
Missable! The puzzle blocks access to the "bonus" skill up console (+2 Skill Points) located inside the vault. You visit this vault during Restoring a World mission.
The puzzle blocks access to the hidden cache which you can find inside the additional vault located in the northwestern part of Voeld.
The puzzles blocks access to the Remnant console. Solving the puzzle is necessary to complete Peebee: Secret Project mission.
The puzzle blocks access to one of the Remnant monoliths located on the planet Kadara. Solving the puzzle is necessary to complete Healing Kadara's Heart mission.
Missable! Skill Points +2. You visit this location during Healing Kadara's Heart mission.
You visit this location during Investigate Remnant Derelict mission.
One of the monoliths (Make This Dust Bowl Livable: Monolith 2) that unlocks the vault on Elaaden. You visit this location during Taming a Desert mission.
Missable! Skill Points +2. You visit this location during Taming a Desert mission.
The puzzle blocks access to the hidden cache inside the additional Remnant vault on Elaaden.
The puzzle blocks access to the hidden cache which you can find inside the additional vault located in in the southern part of Elaaden (east of huge sinkhole).
You visit this location during The Remnant Tiller mission.
Missable! You visit this location during The Journey to Meridian mission.
