The Slate messages are very short encrypted texts found on AS32. They use the XOR cipher with keys from the book Slate Deposits in the Intermountain West.

Each agent code updates daily at 00:00 UTC, uses a different section of the book, and is assigned to different assets:

• 301: Finger of Fate, ID. Assigned to agents who make Dead drops in the US.
• 302: Winston, NM.
• 303: Devils Twist, UT. Assigned to the Shadow Team.

The messages are apparently bidirectional, although we're unaware of how they're submitted yet.

1. “Sequence number ####### start.” The number denotes the key to use from the book, and consists of the year and day of the year.
2. Ciphertext: decimal numbers ranging from 0 to 255 inclusive. If there's no message, this is omitted entirely.
3. “End of message. Cheers.”

• Slate: January 2024