CRYPTO ENGINE
VAULT LOCKED
--:--:-- LOCAL
COMMAND SUITE
◤ PAD CONFIGURATION
PAD DESIGNATION
ROWS GROUPS / ROW
PRINT COPIES
ENTROPY SOURCE: CRYPTO.GETRANDOMVALUES  |  DIGITS: 0-9 UNIFORM (REJECTION SAMPLED)  |  METHOD: RIJMENANTS / AMRRON MOD-10
⇌ OPERATION MODE
ENCRYPT: PLAINTEXT → CHECKERBOARD → PLAINCODE → SUBTRACT PAD (MOD 10) → CIPHERTEXT  |  DECRYPT: CIPHERTEXT → ADD PAD (MOD 10) → PLAINCODE → CHECKERBOARD → PLAINTEXT
▤ PAD SELECTION & KEY INDICATOR
SELECT PAD
START POSITION DIGIT OFFSET — AUTO-SET TO FIRST UNUSED POSITION
KEY INDICATOR
FIRST GROUP OF PAD — PREPENDED TO CIPHERTEXT, NOT USED IN ENCRYPTION
◈ CONVERSION TABLE NO.1 (EN) — RIJMENANTS CHECKERBOARD
SINGLE DIGIT
DOUBLE DIGIT (7x)
DOUBLE DIGIT (8x)
DOUBLE DIGIT (9x) / SPECIAL
FIGURES: PRECEDED & FOLLOWED BY 90(FIG) — EACH DIGIT WRITTEN  |  SPACE=99  |  CODE PREFIX=0(+3-digit codebook value)
▲ PLAINTEXT INPUT
PLAINCODE (CHECKERBOARD CONVERSION)
0 DIGITS
▼ CIPHERTEXT OUTPUT
◈ KEY SEGMENT IN USE (PAD DIGITS — AFTER KEY INDICATOR)
— SELECT A PAD AND ENTER INPUT TO VIEW KEY SEGMENT —
🔐 VAULT ACCESS — AES-256-GCM / PBKDF2
VAULT KEY
VAULT LOCKED — ENTER PASSPHRASE TO ACCESS PAD LIBRARY
FIRST USE: ANY PASSPHRASE INITIALIZES A NEW VAULT. SUBSEQUENT: SAME PASSPHRASE REQUIRED — NOT RECOVERABLE IF LOST.
■ GENERATE DOCUMENTS
Every document printed here is formatted for an 8.5×11 binder page. Each pad sheet carries its ID, designation, the underlined key indicator group, the full key material, and a copy of the Rijmenants conversion table so an operator in the field needs nothing else. Print to paper or “Save as PDF” from the print dialog.
☷ Print Entire Library — Binder Set
Prints every pad in the vault, one pad per page, in matched copies, ready to three-hole-punch. Use this to build the binder set for your group. Requires the vault to be unlocked.
COPIES / PAD A matched pair = one for each station on the net.
▤ Conversion Table Reference Card
Prints a standalone copy of Conversion Table No.1 (EN) — the Rijmenants straddling checkerboard — on its own page. Laminate one for every operator and keep a copy in the front of the binder. No vault required.
□ Single Pad
To print one specific pad, open Pad Library, unlock the vault, and use the ⎟ PRINT button on that pad’s row. The pad you just generated can also be printed straight from Generate Pad with PRINT FIELD SHEETS.
⚠ HANDLING DOCTRINE
•  A one-time pad is secure only if each key segment is used exactly once. Mark pads used after every message.
•  Matched copies must stay matched. If one copy is compromised or lost, destroy its counterpart — never reuse it.
•  Printed pads are plaintext key material. Treat the printout like a loaded weapon: account for every copy, and burn or shred after use.
•  The vault never leaves this machine. Printing is the only way key material leaves the encrypted store — print deliberately.
? USER MANUAL
Full illustrated guide. Hover any acronym for its meaning.
WATCHMAN:CIPHER STATION
ONE-TIME PAD SYSTEM · RIJMENANTS METHOD · MODULE 18

User Manual

Send a message no one can ever read but the person holding the matching pad.
If you can copy down rows of numbers, you can run CIPHER STATION. Read this once, then keep it in the binder.

CIPHER STATION turns a written message into groups of numbers that are mathematically impossible to break when used correctly — the same one-time pad method governments have relied on for a century. This guide assumes you have never seen a one-time pad before and explains everything from zero. Work through it in order the first time. After that, jump to what you need from the table of contents.

CONTENTS

What’s in here

SECTION 1

What a one-time pad is

A one-time pad (OTP) is just a long list of random digits, shared in advance with one other person. You both hold an identical copy. To send a secret message, you combine your message with the next unused digits on the pad using simple addition. The other person reverses it with their matching copy. Then both of you cross those digits off, forever.

The program does four jobs for you:

  • Generates pads full of truly random digits from your computer’s secure random source.
  • Stores them in an encrypted vault so a stolen laptop reveals nothing.
  • Encrypts and decrypts messages for you, tracking exactly which digits have been used.
  • Prints field sheets for the binder so the same pad exists on paper, off the grid.
PLAIN VERSIONThink of a pad as a tear-off notepad of random numbers. Each message tears off a few sheets. Once a sheet is used, it is gone. Because the numbers are random and never reused, there is no pattern for anyone to crack.
SECTION 2

Why it can’t be broken

Most codes can eventually be broken because the key is short and reused, so patterns leak. A one-time pad has no pattern to find: the key is as long as the message, perfectly random, and used only once. For any intercepted message, every possible plaintext is equally likely. An attacker with infinite computing power still learns nothing. This is the only encryption method proven unbreakable — on three conditions:

  1. The key digits are truly random. CIPHER STATION uses your operating system’s cryptographic random source for this.
  2. The key is never reused. Each digit enciphers exactly one digit of one message, ever.
  3. The two copies are kept secret. Anyone who holds a copy can read everything enciphered with it.
THE ONLY WAY TO FAILReusing pad material breaks the guarantee instantly. That is why the program tracks usage and why matched copies must be destroyed together. Follow the handling rules in Section 11 and the math protects you completely.
SECTION 3

What’s on your screen

WATCHMAN : CIPHER STATION COMMAND SUITE ⚙ CIPHER STATION 01 GENERATE PAD 02 ENCRYPT/DECRYPT 03 PAD LIBRARY OUTPUTS ■ GENERATE DOCS HELP ? USER MANUAL PAD CONFIGURATION DESIGNATION / ROWS / GROUPS / COPIES [ ◆ GENERATE PAD ] PAD PREVIEW — ROWS OF RANDOM DIGITS 01 48172 90355 21847 ... 02 77310 64928 13507 ... [ SAVE ] [ PRINT ] [ COPY RAW ]
The Cipher Station screen: top bar, left sidebar (your menu), and the work area
  • A — Top bar. Shows the crypto engine and vault status, a local clock, the link back to COMMAND SUITE, and Settings.
  • B — Left sidebar. Your menu. Click any screen (Generate Pad, Encrypt/Decrypt, Pad Library, Generate Docs, or this manual). The one you are in is highlighted green.
  • C — Work area. Everything you do happens here. It changes with the screen you pick.
SECTION 4

Your first 15 minutes

Do this once with a partner present, or on two machines, to get a working pad on both ends.

  1. Open Pad Library. Type a passphrase and click UNLOCK. The first passphrase you enter creates the vault. Choose something you will not forget — it cannot be recovered.
  2. Open Generate Pad. Give the pad a name (e.g. NET-ALPHA-1), pick a size, set copies to 2, and click GENERATE PAD.
  3. Save it to the library, then print the field sheets. Both printed copies are identical — that is the point.
  4. Give one printed copy to your partner in person. Never send a pad over radio, email, or text. Hand-to-hand only.
  5. Send a test message. Open Encrypt/Decrypt, pick the pad, type HELLO, click EXECUTE, and read the number groups to your partner. They decrypt with their copy. If they get HELLO, you are operational.
  6. Mark the pad used on both ends so those digits are never reused.
TIPGenerate a few pads at once and pre-stage matched copies with each station before a crisis. You cannot safely hand out pads over the air later.
SCREEN 01

Generate Pad

This screen makes new pads full of random digits.

  • Pad designation. A name so you know which net or contact the pad belongs to. Use the same name on both copies.
  • Rows & groups/row. How much key material the pad holds. More rows = more messages before the pad runs out. A 10-row pad holds 500 digits; figure roughly 30–60 digits per short message after conversion.
  • Print copies. How many identical sheets print. Matched pair (2) is the usual choice — one for you, one for the station you talk to.

Click GENERATE PAD and a preview appears. From there you can Save to Library (encrypts it into the vault), Print Field Sheets, or Copy Raw digits.

WHERE THE RANDOMNESS COMES FROMDigits come from crypto.getRandomValues, filtered so all ten digits 0–9 are equally likely. This is real cryptographic randomness, not a predictable computer “random” function.
SCREEN 03

Pad Library & the vault

Your pads live in an encrypted vault on this machine. Nothing is readable until you unlock it with your passphrase.

  • First unlock creates the vault and sets the passphrase. There is no “forgot password.” Lose the passphrase and the pads are gone — which is exactly what protects them if the machine is stolen.
  • Stored pads shows each pad with how much has been used and how much remains. A pad at 100% is spent — generate a new one.
  • Print reprints a single pad. Destroy permanently deletes it (confirm the matching copy is destroyed too).
  • Import pad lets you paste raw digits from a pad made elsewhere — useful for pads handed to you by another operator.
PROTECTED WITH REAL CRYPTOThe vault uses AES-256-GCM with PBKDF2 key stretching. The passphrase never leaves the machine and is never stored.
SCREEN 02

Encrypt / Decrypt

HELLO plaintext 75 2 78 78 5 plaincode (checkerboard) − 90355 21847 key digits (mod 10) 85923 ... ciphertext (send this) PLAINTEXT → CHECKERBOARD → SUBTRACT PAD (MOD 10) → CIPHERTEXT
Encrypt flow. Decrypt is the same in reverse: add the pad back, read the checkerboard

To encrypt: choose ENCRYPT, pick the pad, type your message, click EXECUTE. The output is your ciphertext — number groups you read or relay to the other station. Click COPY OUTPUT to copy it, then MARK PAD USED.

To decrypt: choose DECRYPT, pick the same pad, paste the number groups you received, click EXECUTE. The plaintext appears below.

  • Start position auto-sets to the first unused spot on the pad. Leave it unless you are deliberately coordinating a position with the other operator.
  • Key indicator is the first group, shown for reference. See Section 9.
  • Numbers in your message are handled automatically using the figure-shift rule from the conversion table.
SECTION 8

The conversion table explained

Before the pad math happens, your letters are turned into digits using Conversion Table No.1 (EN) — a straddling checkerboard from the Rijmenants method. You never have to do this by hand — the program does it — but understanding it helps when reading a decrypted message.

Single digitThe six most common letters are one digit each: A=1, E=2, I=3, N=4, O=5, T=6.
Double digitEvery other letter is two digits (B=70, C=71 … Z=89), so common text stays short.
SpaceWritten as 99.
FiguresA run of numbers is wrapped in 90 and each digit written three times, so digits can never be confused with letter codes.
PunctuationPeriod, colon, apostrophe, plus, minus, equals and a request marker have their own 9x codes.

The full table prints on every pad sheet and is available on its own from Generate Docs → Conversion Table Reference Card.

PRACTICAL NOTECommas and apostrophes share one code (93) in the standard table, so a comma reads back as an apostrophe, and the question mark uses the REQ code (98). Keep messages simple: plain words, short sentences. That is normal radio-traffic style anyway.
SECTION 9

Key indicators & matched pairs

The key indicator (KI) is the first five-digit group of the key segment you used. It is sent with the ciphertext but is not used to encrypt anything. Its only job is to tell the receiving station which part of the pad to line up so decryption starts in the right place.

A matched pair is two identical printed copies of one pad. Both stations work from the same digits. When you advance one copy, the other must advance to the same point. The KI in each message keeps the two copies synchronized even if a message is missed.

IN PLAIN TERMSThe key indicator is like saying “start reading at the bookmark” before you read a coded passage aloud. It is not secret and it is not part of the secret.
SCREEN ■

Generate Docs — printing the binder

The Generate Docs screen is where you produce paper for the three-ring binder.

  • Print All Pads (Binder Set). Prints every pad in the vault, one per page, in the number of copies you choose — the fastest way to build the whole binder at once. Vault must be unlocked.
  • Conversion Table Reference Card. Prints the checkerboard on its own page to laminate and keep up front.
  • Single pad. Use the per-pad PRINT button in Pad Library, or PRINT FIELD SHEETS right after generating.

Every sheet is laid out for letter-size paper with the pad ID, designation, copy number, the underlined key-indicator group, the full key grid, and a conversion table — a complete field document needing nothing else.

BINDER TIPPrint the Conversion Table card first as the binder’s front page, then Print All Pads behind it. Three-hole-punch and you have a complete crypto binder for the group.
SECTION 11

Handling rules (OPSEC)

The math is unbreakable. The OPSEC is on you. These rules are not optional:

  1. Never reuse pad material. Mark pads used after every message. Reuse is the one thing that breaks a one-time pad.
  2. Hand-carry pads. Exchange copies in person. Never transmit a pad over any channel you would not trust with the message itself.
  3. Account for every copy. Know where each matched copy is. If one is lost or captured, destroy its counterpart and stop using that pad.
  4. Destroy spent pages. Burn or cross-cut shred used sheets. A printed pad is plaintext key material.
  5. Protect the passphrase. It is the only thing standing between an attacker and your stored pads. It is never recoverable — by design.
AMRRON COMPATIBLEThis pad format follows the AMRRON / Rijmenants mod-10 standard, so pads made here interoperate with operators using the same method on the air.
SECTION 12

Hover any acronym

Anywhere in this manual, a word with a dotted underline like OTP or AMRRON has a definition. Hover your mouse over it to read the plain-language meaning. On a printed copy, see the glossary below.

SECTION 13

Glossary

OTPOne-Time Pad. Random key digits, as long as the message, used exactly once.
PadA stored set of random digits with a name and usage tracking.
PlaintextYour readable message before encryption.
PlaincodeYour message after the checkerboard turns it into digits, before the pad is applied.
CiphertextThe encrypted number groups you transmit.
CheckerboardThe conversion table that turns letters into digits (Conversion Table No.1 EN).
Key indicatorFirst group of the key, sent in the clear, telling the receiver where to start. Not secret.
Matched pairTwo identical copies of a pad, one per station.
Mod 10Add or subtract digits and keep only the last digit (no carrying). The pad arithmetic.
VaultThe encrypted store for your pads, locked by a passphrase.
AES-256-GCMThe strong cipher protecting the vault.
PBKDF2The function that hardens your passphrase against guessing.
AMRRONAmerican Redoubt Radio Operators Network — the preparedness radio group whose pad standard this matches.
OPSECOperational Security — protecting information through careful handling.
SECTION 14

Common questions

Can someone with a supercomputer break this?

No — not if the rules are followed. A correctly used one-time pad is the only encryption proven unbreakable regardless of computing power. The weakness is never the math; it is reuse or a leaked copy.

I forgot my vault passphrase. How do I recover my pads?

You cannot. There is no recovery, by design. Reprint pads from a backup if you have one, or generate new pads and re-exchange copies.

How long does a pad last?

Until its digits run out. The library shows the percentage consumed. Plan one pad per contact and generate fresh pads before the old one is spent.

Can I send this ciphertext over ham radio / voice / text?

Yes. Ciphertext is safe to transmit by any means — that is the whole point. Only the pad itself must stay off the air.

What if my partner and I get out of sync on the pad?

The key indicator in each message tells the receiver exactly where to start, so a missed message will not desync you. If in doubt, agree on a start position in person and both set it manually.

Does my data leave the computer?

No. Pads, the vault, and everything you type stay on this machine. The only way key material leaves is when you deliberately print it.

WATCHMAN:CIPHER STATION
ONE-TIME PAD SYSTEM · RIJMENANTS METHOD · MODULE 18

User Manual

Send a message no one can ever read but the person holding the matching pad.
If you can copy down rows of numbers, you can run CIPHER STATION. Read this once, then keep it in the binder.

CIPHER STATION turns a written message into groups of numbers that are mathematically impossible to break when used correctly — the same one-time pad method governments have relied on for a century. This guide assumes you have never seen a one-time pad before and explains everything from zero. Work through it in order the first time. After that, jump to what you need from the table of contents.

CONTENTS

What’s in here

SECTION 1

What a one-time pad is

A one-time pad (OTP) is just a long list of random digits, shared in advance with one other person. You both hold an identical copy. To send a secret message, you combine your message with the next unused digits on the pad using simple addition. The other person reverses it with their matching copy. Then both of you cross those digits off, forever.

The program does four jobs for you:

  • Generates pads full of truly random digits from your computer’s secure random source.
  • Stores them in an encrypted vault so a stolen laptop reveals nothing.
  • Encrypts and decrypts messages for you, tracking exactly which digits have been used.
  • Prints field sheets for the binder so the same pad exists on paper, off the grid.
PLAIN VERSIONThink of a pad as a tear-off notepad of random numbers. Each message tears off a few sheets. Once a sheet is used, it is gone. Because the numbers are random and never reused, there is no pattern for anyone to crack.
SECTION 2

Why it can’t be broken

Most codes can eventually be broken because the key is short and reused, so patterns leak. A one-time pad has no pattern to find: the key is as long as the message, perfectly random, and used only once. For any intercepted message, every possible plaintext is equally likely. An attacker with infinite computing power still learns nothing. This is the only encryption method proven unbreakable — on three conditions:

  1. The key digits are truly random. CIPHER STATION uses your operating system’s cryptographic random source for this.
  2. The key is never reused. Each digit enciphers exactly one digit of one message, ever.
  3. The two copies are kept secret. Anyone who holds a copy can read everything enciphered with it.
THE ONLY WAY TO FAILReusing pad material breaks the guarantee instantly. That is why the program tracks usage and why matched copies must be destroyed together. Follow the handling rules in Section 11 and the math protects you completely.
SECTION 3

What’s on your screen

WATCHMAN : CIPHER STATION COMMAND SUITE ⚙ CIPHER STATION 01 GENERATE PAD 02 ENCRYPT/DECRYPT 03 PAD LIBRARY OUTPUTS ■ GENERATE DOCS HELP ? USER MANUAL PAD CONFIGURATION DESIGNATION / ROWS / GROUPS / COPIES [ ◆ GENERATE PAD ] PAD PREVIEW — ROWS OF RANDOM DIGITS 01 48172 90355 21847 ... 02 77310 64928 13507 ... [ SAVE ] [ PRINT ] [ COPY RAW ]
The Cipher Station screen: top bar, left sidebar (your menu), and the work area
  • A — Top bar. Shows the crypto engine and vault status, a local clock, the link back to COMMAND SUITE, and Settings.
  • B — Left sidebar. Your menu. Click any screen (Generate Pad, Encrypt/Decrypt, Pad Library, Generate Docs, or this manual). The one you are in is highlighted green.
  • C — Work area. Everything you do happens here. It changes with the screen you pick.
SECTION 4

Your first 15 minutes

Do this once with a partner present, or on two machines, to get a working pad on both ends.

  1. Open Pad Library. Type a passphrase and click UNLOCK. The first passphrase you enter creates the vault. Choose something you will not forget — it cannot be recovered.
  2. Open Generate Pad. Give the pad a name (e.g. NET-ALPHA-1), pick a size, set copies to 2, and click GENERATE PAD.
  3. Save it to the library, then print the field sheets. Both printed copies are identical — that is the point.
  4. Give one printed copy to your partner in person. Never send a pad over radio, email, or text. Hand-to-hand only.
  5. Send a test message. Open Encrypt/Decrypt, pick the pad, type HELLO, click EXECUTE, and read the number groups to your partner. They decrypt with their copy. If they get HELLO, you are operational.
  6. Mark the pad used on both ends so those digits are never reused.
TIPGenerate a few pads at once and pre-stage matched copies with each station before a crisis. You cannot safely hand out pads over the air later.
SCREEN 01

Generate Pad

This screen makes new pads full of random digits.

  • Pad designation. A name so you know which net or contact the pad belongs to. Use the same name on both copies.
  • Rows & groups/row. How much key material the pad holds. More rows = more messages before the pad runs out. A 10-row pad holds 500 digits; figure roughly 30–60 digits per short message after conversion.
  • Print copies. How many identical sheets print. Matched pair (2) is the usual choice — one for you, one for the station you talk to.

Click GENERATE PAD and a preview appears. From there you can Save to Library (encrypts it into the vault), Print Field Sheets, or Copy Raw digits.

WHERE THE RANDOMNESS COMES FROMDigits come from crypto.getRandomValues, filtered so all ten digits 0–9 are equally likely. This is real cryptographic randomness, not a predictable computer “random” function.
SCREEN 03

Pad Library & the vault

Your pads live in an encrypted vault on this machine. Nothing is readable until you unlock it with your passphrase.

  • First unlock creates the vault and sets the passphrase. There is no “forgot password.” Lose the passphrase and the pads are gone — which is exactly what protects them if the machine is stolen.
  • Stored pads shows each pad with how much has been used and how much remains. A pad at 100% is spent — generate a new one.
  • Print reprints a single pad. Destroy permanently deletes it (confirm the matching copy is destroyed too).
  • Import pad lets you paste raw digits from a pad made elsewhere — useful for pads handed to you by another operator.
PROTECTED WITH REAL CRYPTOThe vault uses AES-256-GCM with PBKDF2 key stretching. The passphrase never leaves the machine and is never stored.
SCREEN 02

Encrypt / Decrypt

HELLO plaintext 75 2 78 78 5 plaincode (checkerboard) − 90355 21847 key digits (mod 10) 85923 ... ciphertext (send this) PLAINTEXT → CHECKERBOARD → SUBTRACT PAD (MOD 10) → CIPHERTEXT
Encrypt flow. Decrypt is the same in reverse: add the pad back, read the checkerboard

To encrypt: choose ENCRYPT, pick the pad, type your message, click EXECUTE. The output is your ciphertext — number groups you read or relay to the other station. Click COPY OUTPUT to copy it, then MARK PAD USED.

To decrypt: choose DECRYPT, pick the same pad, paste the number groups you received, click EXECUTE. The plaintext appears below.

  • Start position auto-sets to the first unused spot on the pad. Leave it unless you are deliberately coordinating a position with the other operator.
  • Key indicator is the first group, shown for reference. See Section 9.
  • Numbers in your message are handled automatically using the figure-shift rule from the conversion table.
SECTION 8

The conversion table explained

Before the pad math happens, your letters are turned into digits using Conversion Table No.1 (EN) — a straddling checkerboard from the Rijmenants method. You never have to do this by hand — the program does it — but understanding it helps when reading a decrypted message.

Single digitThe six most common letters are one digit each: A=1, E=2, I=3, N=4, O=5, T=6.
Double digitEvery other letter is two digits (B=70, C=71 … Z=89), so common text stays short.
SpaceWritten as 99.
FiguresA run of numbers is wrapped in 90 and each digit written three times, so digits can never be confused with letter codes.
PunctuationPeriod, colon, apostrophe, plus, minus, equals and a request marker have their own 9x codes.

The full table prints on every pad sheet and is available on its own from Generate Docs → Conversion Table Reference Card.

PRACTICAL NOTECommas and apostrophes share one code (93) in the standard table, so a comma reads back as an apostrophe, and the question mark uses the REQ code (98). Keep messages simple: plain words, short sentences. That is normal radio-traffic style anyway.
SECTION 9

Key indicators & matched pairs

The key indicator (KI) is the first five-digit group of the key segment you used. It is sent with the ciphertext but is not used to encrypt anything. Its only job is to tell the receiving station which part of the pad to line up so decryption starts in the right place.

A matched pair is two identical printed copies of one pad. Both stations work from the same digits. When you advance one copy, the other must advance to the same point. The KI in each message keeps the two copies synchronized even if a message is missed.

IN PLAIN TERMSThe key indicator is like saying “start reading at the bookmark” before you read a coded passage aloud. It is not secret and it is not part of the secret.
SCREEN ■

Generate Docs — printing the binder

The Generate Docs screen is where you produce paper for the three-ring binder.

  • Print All Pads (Binder Set). Prints every pad in the vault, one per page, in the number of copies you choose — the fastest way to build the whole binder at once. Vault must be unlocked.
  • Conversion Table Reference Card. Prints the checkerboard on its own page to laminate and keep up front.
  • Single pad. Use the per-pad PRINT button in Pad Library, or PRINT FIELD SHEETS right after generating.

Every sheet is laid out for letter-size paper with the pad ID, designation, copy number, the underlined key-indicator group, the full key grid, and a conversion table — a complete field document needing nothing else.

BINDER TIPPrint the Conversion Table card first as the binder’s front page, then Print All Pads behind it. Three-hole-punch and you have a complete crypto binder for the group.
SECTION 11

Handling rules (OPSEC)

The math is unbreakable. The OPSEC is on you. These rules are not optional:

  1. Never reuse pad material. Mark pads used after every message. Reuse is the one thing that breaks a one-time pad.
  2. Hand-carry pads. Exchange copies in person. Never transmit a pad over any channel you would not trust with the message itself.
  3. Account for every copy. Know where each matched copy is. If one is lost or captured, destroy its counterpart and stop using that pad.
  4. Destroy spent pages. Burn or cross-cut shred used sheets. A printed pad is plaintext key material.
  5. Protect the passphrase. It is the only thing standing between an attacker and your stored pads. It is never recoverable — by design.
AMRRON COMPATIBLEThis pad format follows the AMRRON / Rijmenants mod-10 standard, so pads made here interoperate with operators using the same method on the air.
SECTION 12

Hover any acronym

Anywhere in this manual, a word with a dotted underline like OTP or AMRRON has a definition. Hover your mouse over it to read the plain-language meaning. On a printed copy, see the glossary below.

SECTION 13

Glossary

OTPOne-Time Pad. Random key digits, as long as the message, used exactly once.
PadA stored set of random digits with a name and usage tracking.
PlaintextYour readable message before encryption.
PlaincodeYour message after the checkerboard turns it into digits, before the pad is applied.
CiphertextThe encrypted number groups you transmit.
CheckerboardThe conversion table that turns letters into digits (Conversion Table No.1 EN).
Key indicatorFirst group of the key, sent in the clear, telling the receiver where to start. Not secret.
Matched pairTwo identical copies of a pad, one per station.
Mod 10Add or subtract digits and keep only the last digit (no carrying). The pad arithmetic.
VaultThe encrypted store for your pads, locked by a passphrase.
AES-256-GCMThe strong cipher protecting the vault.
PBKDF2The function that hardens your passphrase against guessing.
AMRRONAmerican Redoubt Radio Operators Network — the preparedness radio group whose pad standard this matches.
OPSECOperational Security — protecting information through careful handling.
SECTION 14

Common questions

Can someone with a supercomputer break this?

No — not if the rules are followed. A correctly used one-time pad is the only encryption proven unbreakable regardless of computing power. The weakness is never the math; it is reuse or a leaked copy.

I forgot my vault passphrase. How do I recover my pads?

You cannot. There is no recovery, by design. Reprint pads from a backup if you have one, or generate new pads and re-exchange copies.

How long does a pad last?

Until its digits run out. The library shows the percentage consumed. Plan one pad per contact and generate fresh pads before the old one is spent.

Can I send this ciphertext over ham radio / voice / text?

Yes. Ciphertext is safe to transmit by any means — that is the whole point. Only the pad itself must stay off the air.

What if my partner and I get out of sync on the pad?

The key indicator in each message tells the receiver exactly where to start, so a missed message will not desync you. If in doubt, agree on a start position in person and both set it manually.

Does my data leave the computer?

No. Pads, the vault, and everything you type stay on this machine. The only way key material leaves is when you deliberately print it.

WATCHMAN : CIPHER STATION  ·  © 2026 WATCHMAN Suite, LLC. All rights reserved.  ·  RIJMENANTS METHOD // MOD-10 DIGIT PAD // AMRRON COMPATIBLE  ·  BUILD 202603271943 SECURE ENCLAVE ACTIVE
Settings
Color Mode
Applies to all modules in the suite
Dark is the default tactical display. Light / Operator mode uses a field manual aesthetic.
SUITEWATCHMAN COMMAND SUITE
MODULECIPHER STATION
VERSION1.1 — July 2026
PUBLISHERWATCHMAN Suite, LLC
COPYRIGHT© 2026 WATCHMAN Suite, LLC. All rights reserved.