CIP-0160, CIP-0019 | Specify per-output Receiving and protected addresses

CIP-0019/CIP-0019-cardano-addresses.abnf

@@ -1,18 +1,27 @@
-ADDRESS = %b0000 | NETWORK-TAG | KEY-HASH    | KEY-HASH       ; type 00, Base Shelley address
-        \ %b0001 | NETWORK-TAG | SCRIPT-HASH | KEY-HASH       ; type 01, Base Shelley address
-        \ %b0010 | NETWORK-TAG | KEY-HASH    | SCRIPT-HASH    ; type 02, Base Shelley address
-        \ %b0011 | NETWORK-TAG | SCRIPT-HASH | SCRIPT-HASH    ; type 03, Base Shelley address
+ADDRESS = %b0000 | PAYMENT-ADDRESS-TAG | KEY-HASH    | KEY-HASH       ; type 00, Base Shelley address
+        \ %b0001 | PAYMENT-ADDRESS-TAG | SCRIPT-HASH | KEY-HASH       ; type 01, Base Shelley address
+        \ %b0010 | PAYMENT-ADDRESS-TAG | KEY-HASH    | SCRIPT-HASH    ; type 02, Base Shelley address
+        \ %b0011 | PAYMENT-ADDRESS-TAG | SCRIPT-HASH | SCRIPT-HASH    ; type 03, Base Shelley address
         \ %b0100 | NETWORK-TAG | KEY-HASH    | POINTER        ; type 04, Pointer Shelley address deprecated in Conway
         \ %b0101 | NETWORK-TAG | SCRIPT-HASH | POINTER        ; type 05, Pointer Shelley address deprecated in Conway
-        \ %b0110 | NETWORK-TAG | KEY-HASH                     ; type 06, Payment Shelley address
-        \ %b0111 | NETWORK-TAG | SCRIPT-HASH                  ; type 07, Payment Shelley address
+        \ %b0110 | PAYMENT-ADDRESS-TAG | KEY-HASH                     ; type 06, Payment Shelley address
+        \ %b0111 | PAYMENT-ADDRESS-TAG | SCRIPT-HASH                  ; type 07, Payment Shelley address
         \ %b1000 | BYRON-PAYLOAD                              ; type 08, Byron / Bootstrap address
         \ %b1110 | NETWORK-TAG | KEY-HASH                     ; type 14, Stake Shelley address
         \ %b1111 | NETWORK-TAG | SCRIPT-HASH                  ; type 15, Stake Shelley address
 
 NETWORK-TAG  = %b0000 ; Testnet
              \ %b0001 ; Mainnet
 
+; Proposed CIP-160 extension: PROTECTED-NETWORK-TAG is valid only after
+; the agreed activation. It applies to base/enterprise payment families above;
+; pointer, reward/account and Byron addresses do not gain a protection flag.
+PAYMENT-ADDRESS-TAG = NETWORK-TAG
+                    \ PROTECTED-NETWORK-TAG
+
+PROTECTED-NETWORK-TAG = %b1000 ; Protected testnet (network bit 0)
+                      \ %b1001 ; Protected mainnet (network bit 1)
+
 POINTER = VARIABLE-LENGTH-UINT ; slot number
         | VARIABLE-LENGTH-UINT ; transaction index
         | VARIABLE-LENGTH-UINT ; certificate index

CIP-0019/README.md

@@ -50,7 +50,7 @@ Examples of different addresses encoded in different eras:
 
 In Cardano, the sequence of bytes (after decoding with Bech32 or Base58) that represents an address  comprises two parts, a one-byte **header** and a **payload** of several bytes. Depending on the header, the interpretation and length of the payload varies. 
 
-In the header-byte, bits [7;4] indicate the type of addresses being used; we'll call these four bits the **header type**. The remaining four bits [3;0] are either unused or refer to what we'll call the **network tag**. There are currently 11 types of addresses in Cardano which we'll divide into three categories: [Shelley addresses], [stake addresses], and [Byron addresses]. 
+In the header-byte, bits [7;4] indicate the type of addresses being used; we'll call these four bits the **header type**. In the currently activated format, the remaining four bits [3;0] are either unused or refer to what we'll call the **network tag**. The proposed CIP-160 payment-address extension below reserves bit 3 for protection in specified families; it does not change the activated network definitions. There are currently 11 types of addresses in Cardano which we'll divide into three categories: [Shelley addresses], [stake addresses], and [Byron addresses].
 
 ```
   1 byte     variable length   
@@ -77,6 +77,46 @@ Network Tag (`. . . . n n n n`)   | Semantic
 `....0001`                        | Mainnet
 
 
+#### Proposed protected payment-address extension
+
+[CIP-160](../CIP-0160/README.md) proposes opt-in creation authorization for
+Shelley payment addresses. This section specifies the candidate byte format;
+it is not an assertion of mainnet activation or Ledger/Plutus acceptance.
+Acceptance and activation of this extension remain subject to CIP-160's
+criteria and an agreed future-era protocol version.
+
+For base types 0–3 and enterprise types 6–7, bit 3 (`0x08`) of the header is
+the proposed protection flag. Bits 1–2 remain reserved and zero; bit 0 retains
+the network meaning below. Existing high-nibble types, credential payloads and
+lengths are unchanged.
+
+| Payment low nibble (`p 0 0 n`) | Protection | Network |
+| --- | --- | --- |
+| `0000` | Unprotected | Testnet(s) |
+| `0001` | Unprotected | Mainnet |
+| `1000` | Protected | Testnet(s) |
+| `1001` | Protected | Mainnet |
+
+`1000` and `1001` in these families do not introduce network types 8 and 9.
+Network-aware code interprets protection separately from network identity.
+Other low-nibble values remain reserved. Header examples are protected base
+key/key `0x08`/`0x09` and protected enterprise script `0x78`/`0x79` on
+testnet/mainnet, respectively.
+
+Pointer types 4–5, Byron type 8, stake types 14–15, account addresses and other
+families do not support protection. Their formats/network interpretation are
+unchanged; setting `0x08` does not make them protected payment addresses.
+Protected pointers and malformed protected payloads are invalid. A protected
+address uses the existing `addr` or `addr_test` prefix and is distinct from an
+unprotected address carrying the same credentials. Unprotected examples below
+remain unchanged. The [proposed vectors](../CIP-0160/test-vectors/protected-addresses.json)
+derive protected bytes from those same examples.
+
+The annex's `PAYMENT-ADDRESS-TAG` extension applies only after this feature's
+activation. Historical-era parsers and transactions retain their existing
+acceptance domain; recognizing the candidate raw format does not establish
+transaction eligibility.
+
 #### Shelley Addresses 
 
 There are currently 8 types of Shelley addresses summarized in the table below: