XLS: Confidential Multi-Purpose Tokens (Draft) #460

mrtcnk · 2026-02-10T18:56:32Z

Draft XLS for Confidential Multi-Purpose Tokens.
This brings the spec closer to the current implementation; follow-up PRs may address naming and minor discrepancies.

Co-authored-by: Shawn Xie <[email protected]>

fix: auditor policy

XLS-????-ConfidentialMPT/README.md

mvadari · 2026-02-10T19:06:11Z

XLS-????-ConfidentialMPT/README.md

+    author: Murat Cenk <[email protected]>, Aanchal Malhotra <[email protected]>, Ayo Akinyele <[email protected]>
+    status: Ongoing
+    category: Amendment
+    created: Jan 15, 2026


Suggested change

created: Jan 15, 2026

created: 2026-01-15

Tapanito · 2026-02-11T15:32:51Z

XLS-0096-confidential-mpt/README.md

+    description: This amendment introduces Confidential Multi-Purpose Tokens (MPTs) on the XRP Ledger.
+    author: Murat Cenk <[email protected]>, Aanchal Malhotra <[email protected]>, Ayo Akinyele <[email protected]>
+    status: Ongoing
+    category: Amendment


Suggested change

category: Amendment

category: Amendment

requires: XLS-33

Tapanito · 2026-02-11T15:33:14Z

xls-draft-confidential-mpt/README.md

@@ -0,0 +1,862 @@
+<pre>
+    title:  Confidential Multi-Purpose Tokens for XRPL


title: Confidential Multi-Purpose Tokens

Tapanito · 2026-02-11T15:33:25Z

xls-draft-confidential-mpt/README.md

+    created: Jan 15, 2026
+</pre>
+
+# Confidential Multi-Purpose Tokens for XRPL


Confidential Multi-Purpose Tokens

Tapanito · 2026-02-11T15:34:57Z

xls-draft-confidential-mpt/README.md

+
+MPTokenIssuance Extensions: To support confidential MPTs, the MPTokenIssuance ledger object is extended with two new flags and three new fields. These serve as the global configuration and control settings for the token's confidential features.
+
+### 3.2.1 New Flags:


The flags should be declared and defined where they're used.

Tapanito · 2026-02-11T15:35:11Z

xls-draft-confidential-mpt/README.md

+- lsfMPTCanPrivacy: If set, indicates that confidential transfers and conversions are enabled for this token issuance.
+- lsmfMPTCannotMutatePrivacy: If set, the lsfMPTCanPrivacy flag can never be changed after the token is issued, permanently locking the confidentiality setting.
+
+### 3.2.3 New Fields:


New fields should be declared and defined where they're used.

Tapanito · 2026-02-11T15:49:16Z

xls-draft-confidential-mpt/README.md

+
+The existing `MPTokenIssuanceSet` transaction is extended to manage the confidential lifecycle of an MPT issuance. This includes enabling/disabling privacy status and registering encryption keys.
+
+### 11.1. New Fields


Suggested change

### 11.1. New Fields

### 11.1. Fields

Tapanito · 2026-02-11T15:49:33Z

xls-draft-confidential-mpt/README.md

+| `IssuerElGamalPublicKey`  | The 33-byte EC-ElGamal public key used for the issuer's mirror balances.         |
+| `AuditorElGamalPublicKey` | The 33-byte EC-ElGamal public key used for regulatory oversight (if applicable). |
+
+### 11.2. Usage & Mutability


This should be moved before fields.

Tapanito · 2026-02-11T15:50:00Z

XLS-0096-confidential-mpt/README.md

+
+- **Flags:** The `lsfMPTCanPrivacy` flag is updated (if mutable).
+- **Keys:** The `sfIssuerElGamalPublicKey` and/or `sfAuditorElGamalPublicKey` are stored on the `MPTokenIssuance` ledger entry.
+


Could you add an example JSON please.

Tapanito · 2026-02-11T15:50:53Z

xls-draft-confidential-mpt/README.md

+
+Confidential MPTs introduce cryptographic mechanisms that require careful validation and enforcement. This section summarizes key security invariants, proof requirements, and considerations against potential attack vectors.
+
+### Proof Requirements


Could you please add subsection indexes. E.g. 14.1., 14.2., etc.

Tapanito · 2026-02-11T15:51:40Z

xls-draft-confidential-mpt/README.md

+
+Bulletproofs are an efficient choice. Even when reducing the bit length, the decomposition approach results in a transaction payload that is over 6 times larger than a Bulletproof.
+
+## 16. Frequently Asked Questions (FAQ)


The FAQ should go into the appendix:

# Appendix _(Optional)_ ## Appendix A: FAQ _(Optional)_ _[A list of questions the author expects to be asked about the spec, and their answers. It is highly recommended but not required to include this section, to make it easier for spec readers to understand it.]_ ### A.1: [Question] _[Answer to the question]_

Tapanito · 2026-02-11T15:54:59Z

Thank you for rewriting the specification @mrtcnk , it's in a much better state. I left some editorial comments, once they've been addressed, I'll do a technical review of the transactors.

github-actions · 2026-02-11T16:31:56Z

🎫 XLS Number Assignment

This PR adds a new XLS draft. The next available XLS number has been determined:

Draft Directory	Assigned Number	New Directory Name
`xls-draft-confidential-mpt`	XLS-96	`xls-0096-confidential-mpt`

Next Steps for XLS Editors

Before merging this PR, please:

Rename the directory from xls-draft-confidential-mpt to xls-0096-confidential-mpt
Update the preamble in the README.md:
- Set xls: to 96
- Set status: to Draft

This comment was automatically generated. The XLS number is based on the highest existing number in the repository at the time this PR was opened.

Correct commitment field names

mvadari · 2026-02-11T21:06:15Z

@mrtcnk you can now update the XLS number based on the bot's comment 🙂

mvadari · 2026-02-11T21:10:52Z

xls-draft-confidential-mpt/README.md

+The protocol relies on a set of ZKPs to validate confidential transactions without revealing balances or transfer amounts. The following proof types are used:
+
+- **Plaintext–ciphertext equality proofs:** Prove that a publicly known amount `m` is correctly encrypted.
+


nit: I recommend removing the spaces between these bullets for consistency/readability (same with in the other sections)

mvadari · 2026-02-12T15:39:31Z

XLS-0096-confidential-mpt/README.md

@@ -0,0 +1,865 @@
+<pre>


Please rename the folder as per the bot comment

Done in the latest push.

fix comments

mrtcnk · 2026-02-13T04:19:08Z

Thank you for the detailed review @Tapanito @mvadari . The comments have been addressed and updates have been pushed.

mrtcnk added 30 commits June 5, 2025 13:57

Create xls-confidential-transfer.md

82ac2f4

Rename xls-confidential-transfer.md to READ.me

6b16a18

Fixed typo

35ab4e3

Update READ.md

045b3c0

Update READ.md

4afc20b

Update READ.md

84490a8

Update READ.md

8be3cf8

Update READ.md

6fef4d0

Update READ.md

8fef263

Update READ.md

c307efc

Update READ.md

651f970

Update READ.md

763360f

Update READ.md

0922446

Update READ.md

94875f8

Update READ.md

401b435

Update READ.md

ef97587

Update READ.md

6d912d5

Update READ.md

29bea96

Update READ.md

8697ff3

Update READ.md

0384a71

Update READ.md

ba0ab07

Update READ.md

8052f09

Update READ.md

cc58c66

Update READ.md

d45a2c8

Update READ.md

1dc33c2

Update READ.md

8ebaecf

Update READ.md

568ac0c

Update READ.md

0d4790b

Update READ.md

bd61697

Update READ.md

e60fe08

PeterChen13579 and others added 7 commits February 10, 2026 10:22

Update XLS-????-ConfidentialMPT/README.md

a915076

Co-authored-by: Shawn Xie <[email protected]>

Merge pull request #3 from PeterChen13579/new_branch

a37411f

fix: auditor policy

XLS: add Confidential MPT draft

78cc44e

XLS: add Confidential MPT draft

e0ec9ee

Delete xrpl-draft-confidential-mpt directory

4b81ca6

XLS: add Confidential MPT draft

99914c2

Delete XLS-draft-confidential-mpt directory

3e8ef1c

mvadari reviewed Feb 10, 2026

View reviewed changes

XLS-????-ConfidentialMPT/README.md Outdated Show resolved Hide resolved

mvadari reviewed Feb 10, 2026

View reviewed changes

mrtcnk and others added 2 commits February 10, 2026 14:13

Delete XLS-????-ConfidentialMPT directory

0035272

Merge branch 'master' into xls-draft-confidential-mpt

89413dc

Tapanito requested changes Feb 11, 2026

View reviewed changes

shawnxie999 and others added 2 commits February 11, 2026 11:15

rename commitment

0ae7fb4

Merge branch 'master' into xls-draft-confidential-mpt

ae5488b

mrtcnk and others added 2 commits February 11, 2026 15:36

Merge pull request #4 from shawnxie999/ct-change-pc

ec0e812

Correct commitment field names

Merge branch 'master' into xls-draft-confidential-mpt

60f85cd

mvadari mentioned this pull request Feb 11, 2026

fix bot text to properly handle numbers #466

Merged

1 task

mvadari reviewed Feb 11, 2026

View reviewed changes

mrtcnk added 2 commits February 11, 2026 17:03

address initial reviewer feedback

8f275be

address initial reviewer feedback

110d735

mvadari reviewed Feb 12, 2026

View reviewed changes

PeterChen13579 and others added 3 commits February 12, 2026 14:36

fix comments

43aea4d

Merge pull request #5 from PeterChen13579/fix_comments

734e022

fix comments

Assign XLS number, rename directory, update spec and FAQ sections

7542b36

mhotrodriguez-hue approved these changes Feb 13, 2026

View reviewed changes

		@@ -0,0 +1,862 @@
		<pre>
		title: Confidential Multi-Purpose Tokens for XRPL


		MPTokenIssuance Extensions: To support confidential MPTs, the MPTokenIssuance ledger object is extended with two new flags and three new fields. These serve as the global configuration and control settings for the token's confidential features.

		### 3.2.1 New Flags:


		The existing `MPTokenIssuanceSet` transaction is extended to manage the confidential lifecycle of an MPT issuance. This includes enabling/disabling privacy status and registering encryption keys.

		### 11.1. New Fields


		- Flags: The `lsfMPTCanPrivacy` flag is updated (if mutable).
		- Keys: The `sfIssuerElGamalPublicKey` and/or `sfAuditorElGamalPublicKey` are stored on the `MPTokenIssuance` ledger entry.


		Confidential MPTs introduce cryptographic mechanisms that require careful validation and enforcement. This section summarizes key security invariants, proof requirements, and considerations against potential attack vectors.

		### Proof Requirements


		Bulletproofs are an efficient choice. Even when reducing the bit length, the decomposition approach results in a transaction payload that is over 6 times larger than a Bulletproof.

		## 16. Frequently Asked Questions (FAQ)

		The protocol relies on a set of ZKPs to validate confidential transactions without revealing balances or transfer amounts. The following proof types are used:

		- Plaintext–ciphertext equality proofs: Prove that a publicly known amount `m` is correctly encrypted.

XLS: Confidential Multi-Purpose Tokens (Draft) #460

Are you sure you want to change the base?

XLS: Confidential Multi-Purpose Tokens (Draft) #460

Uh oh!

Conversation

mrtcnk commented Feb 10, 2026

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Confidential Multi-Purpose Tokens

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Tapanito commented Feb 11, 2026

Uh oh!

github-actions bot commented Feb 11, 2026 • edited by mvadari Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

🎫 XLS Number Assignment

Next Steps for XLS Editors

Uh oh!

mvadari commented Feb 11, 2026

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

mrtcnk commented Feb 13, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

6 participants

github-actions bot commented Feb 11, 2026 •

edited by mvadari

Loading