Redshirt

File Format
Name	Redshirt
Ontology	Electronic File Formats Encryption Redshirt
Magic Bytes	52 45 44 53 48 49 52 54 (REDSHIRT) 4F 4E 45 54 49 4D 45 52 45 44 53 48 49 52 54 (ONETIMEREDSHIRT)
Released	2001

Redshirt was used in the Uplink (video game) to bring challenges towards players who are curious in nature. The featured game itself is about computer hacking, so the pseudo encryption was used to encrypt save games for instance to prevent players cheating the game, or by encrypting portions of game assets to cater for easter eggs, like the game bible series that were distributed on separate discs or shared on peer-to-peer file sharing software like Kazaa.

Earlier versions of Redshirt uses simple XOR encryption scheme Latter revisions incorporated features like one-time-pad (OTP) encryption. Certain revisions of redshirt2 used a different technique.

Identification

Redshirt typically begins with HEX 52 45 44 53 48 49 52 54 which corresponds to ASCII string "REDSHIRT". Redshirt with one-time-pad (OTP) encryption begins with HEX 4F 4E 45 54 49 4D 45 52 45 44 53 48 49 52 54 which corresponds to ASCII string " ONETIMEREDSHIRT".

Software

Windows

• https://web.archive.org/web/20040219012231/http://www.stewsburntmonkey.com/redshirt.exe
• Uplink Developer CD has these under tools folder.

Linux/Unix

• http://www.mario-konrad.ch/blog/software/redshirt/index.html

Macintosh

• http://www.cytheraguides.com/archives/ambrosia_addons/uplink/ - the file in question is called "RedshirtX.sit"

Non-OS specific

Python

• How can I break REDSHIRT / REDSHIRT2 encryption? - Stack Exchange

Rust

• https://lib.rs/crates/redshirt - upstream repository: https://github.com/FaultyRAM/redshirt-rs

Sample files

• data.dat - Uplink 1.3.3 - Ambrosia Software CD-ROM (Ambrosia Software, Inc.)(2002).bin - Discmaster.textfiles.com
• world.dat - Uplink 1.3.3 - Ambrosia Software CD-ROM (Ambrosia Software, Inc.)(2002).bin - Discmaster.textfiles.com