Upon arriving in the cyberpunk town of Repine you'll be greeted by a little bit of a puzzle, assuming you look around. If you check inside the weapons shop - it's to the south and on the right of Seraï's home, in the north of Repine, and has a green neon sign over the entrance - you'll find a locked door on your right. The door refuses to open unless you have a Cypher, and in order to procure a Cypher you'll need four Data Strips.
This guide will help you find the four Data Strips in Sea of Stars. They're spread throughout Seraï's World, and though none of them are terribly difficult to find it's still easy to miss one or two as you're exploring.
Data Strip #1 - Speedball Network Station
The first Data Strip you can potentially find is inside the Speedball Network Station sitting on an island by itself. You can sail to this location immediately after arriving in Seraï's World, as it's a quick jaunt north of the whirlpool that leads back to Home World. The Data Strip is in a chest to the left of the giant speedball.
Data Strip #2 - Repine
The second Data Strip is in Repine itself. Head to the entrance of Repine, then look on your right. There's a Speedball Network Station over here, and next to it is an alleyway that leads north. Walk to the end of the alleyway - you'll cross beneath a bridge if you're headed in the right direction - and you'll find the chest containing the Data Strip.
Data Strip #3 - Cerulean Reservoir
The third Data Strip is at the Cerulean Reservoir, the Fishing Lake a short walk east of Repine. Head up to the pool and jump in. Swim to the north end and you'll find the chest containing the Data Strip.
Data Strip #4 - Fleshmancer's Lair
The fourth and final Data Strip will force you to put this little quest aside for a while, as it's located in the Fleshmancer's Lair, the final dungeon of the game. Head to the second area from the entrance - the chamber where you need to push around giant eyeballs - then complete the puzzle inside. Near the end of the puzzle you'll see a chest in the northeast that's protected by stalagmites. Roll one of the eyeballs through the stalagmites to get at the chest, which contains the fourth Data Strip.
The Cypher
Now that you have all four Data Strips you need to put them together. Head back to Seraï's home in Repine and inspect the computer console on the left side of the room. If you've collected every Data Strip Cedric will merge them together into a Cypher.
Take the Cypher to the weapon shop and open the locked door. Inside the door you'll find two chests. One contains Question Pack #9, a necessity for completing the quiz side quest, while the other contains a Cosmic Cape for Resh'an. Not too shabby.