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Dual MIT/Apache-2.0 License

     

       
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Copyright (c) 2022-2024 Bluesky PBC

     

       
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Except as otherwise noted in individual files, this software is licensed under the MIT license (<http://opensource.org/licenses/MIT>), or the Apache License, Version 2.0 (<http://www.apache.org/licenses/LICENSE-2.0>), at your option.

     

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Dual MIT/Apache-2.0 License

     

       
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+
       
Copyright (c) 2022-2025 Bluesky Social PBC

     

       
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Except as otherwise noted in individual files, this software is licensed under the MIT license (<http://opensource.org/licenses/MIT>), or the Apache License, Version 2.0 (<http://www.apache.org/licenses/LICENSE-2.0>), at your option.

     

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## Motivation

     

       
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-
       
[Bluesky PBC](https://bsky.social/) developed DID PLC when designing the [AT Protocol](https://atproto.com) (atproto) because we were not satisfied with any of the existing DID methods. We wanted a strongly consistent, highly available, recoverable, and cryptographically secure method with fast and cheap propagation of updates.

     

       
14
       
 
       


     

       
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PLC stands for "Public Ledger of Credentials". We expect to evolve the system (in a backwards-compatible manner) into something less centralized - likely a permissioned DID consortium. That being said, we do intend to support `did:plc` in the current form until after any successor is deployed, with a reasonable grace period. We would also provide a migration route to allow continued use of existing `did:plc` identifiers.

     

       
16
       
 
       


     
···

       
389
       
 
       


     

       
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We welcome proposals for small additions to make `did:plc` more generic and reusable for applications other than atproto. But no promises: atproto will remain the focus for the near future.

     

       
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We are enthusiastic about the prospect of moving governance of the `did:plc` method, and operation of registry servers, out of the sole control of Bluesky PBC. Audit log snapshots, mirroring, and automated third-party auditing have all been considered as mechanisms to mitigate the centralized nature of the PLC server.

     

       
393
       
 
       


     

       
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The size of the `verificationMethods`, `alsoKnownAs`, and `service` mappings/arrays may be specifically constrained. And the maximum DAG-CBOR size may be constrained.

     

       
395
       
 
       


     

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10
       
 
       


     

       
11
       
 
       
## Motivation

     

       
12
       
 
       


     

       
13
       
+
       
[Bluesky Social PBC](https://bsky.social/) developed DID PLC when designing the [AT Protocol](https://atproto.com) (atproto) because we were not satisfied with any of the existing DID methods. We wanted a strongly consistent, highly available, recoverable, and cryptographically secure method with fast and cheap propagation of updates.

     

       
14
       
 
       


     

       
15
       
 
       
PLC stands for "Public Ledger of Credentials". We expect to evolve the system (in a backwards-compatible manner) into something less centralized - likely a permissioned DID consortium. That being said, we do intend to support `did:plc` in the current form until after any successor is deployed, with a reasonable grace period. We would also provide a migration route to allow continued use of existing `did:plc` identifiers.

     

       
16
       
 
       


     
···

       
389
       
 
       


     

       
390
       
 
       
We welcome proposals for small additions to make `did:plc` more generic and reusable for applications other than atproto. But no promises: atproto will remain the focus for the near future.

     

       
391
       
 
       


     

       
392
       
+
       
We are enthusiastic about the prospect of moving governance of the `did:plc` method, and operation of registry servers, out of the sole control of Bluesky Social PBC. Audit log snapshots, mirroring, and automated third-party auditing have all been considered as mechanisms to mitigate the centralized nature of the PLC server.

     

       
393
       
 
       


     

       
394
       
 
       
The size of the `verificationMethods`, `alsoKnownAs`, and `service` mappings/arrays may be specifically constrained. And the maximum DAG-CBOR size may be constrained.

     

       
395
       
 
       


     

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  "name": "did-method-plc",

     

       
3
       
 
       
  "version": "0.0.1",

     

       
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  "repository": "git@github.com:did-method-plc/did-method-plc.git",

     

       
5
       
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  "author": "Bluesky PBC <hello@blueskyweb.xyz>",

     

       
6
       
 
       
  "license": "MIT",

     

       
7
       
 
       
  "private": true,

     

       
8
       
 
       
  "engines": {

     

···

       
2
       
 
       
  "name": "did-method-plc",

     

       
3
       
 
       
  "version": "0.0.1",

     

       
4
       
 
       
  "repository": "git@github.com:did-method-plc/did-method-plc.git",

     

       
5
       
+
       
  "author": "Bluesky Social PBC <hello@blueskyweb.xyz>",

     

       
6
       
 
       
  "license": "MIT",

     

       
7
       
 
       
  "private": true,

     

       
8
       
 
       
  "engines": {

     

···

       
381
       
 
       


     

       
382
       
 
       
We welcome proposals for small additions to make `did:plc` more generic and reusable for applications other than atproto. But no promises: atproto will remain the focus for the near future.

     

       
383
       
 
       


     

       
384
       
-
       
We are enthusiastic about the prospect of moving governance of the `did:plc` method, and operation of registry servers, out of the sole control of Bluesky PBC. Audit log snapshots, mirroring, and automated third-party auditing have all been considered as mechanisms to mitigate the centralized nature of the PLC server.

     

       
385
       
 
       


     

       
386
       
 
       
The size of the `verificationMethods`, `alsoKnownAs`, and `service` mappings/arrays may be specifically constrained. And the maximum DAG-CBOR size may be constrained.

     

       
387
       
 
       


     

···

       
381
       
 
       


     

       
382
       
 
       
We welcome proposals for small additions to make `did:plc` more generic and reusable for applications other than atproto. But no promises: atproto will remain the focus for the near future.

     

       
383
       
 
       


     

       
384
       
+
       
We are enthusiastic about the prospect of moving governance of the `did:plc` method, and operation of registry servers, out of the sole control of Bluesky Social PBC. Audit log snapshots, mirroring, and automated third-party auditing have all been considered as mechanisms to mitigate the centralized nature of the PLC server.

     

       
385
       
 
       


     

       
386
       
 
       
The size of the `verificationMethods`, `alsoKnownAs`, and `service` mappings/arrays may be specifically constrained. And the maximum DAG-CBOR size may be constrained.

     

       
387
       
 
       


     

···

       
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<footer class="container-fluid">

     

       
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	<div class="container">

     

       
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-
       
    <small>Developed by <a href="https://bsky.social">Bluesky PBC</a> for <a href="https://atproto.com">atproto</a></small>

     

       
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  </div>

     

       
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</footer>

     

       
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{% endblock -%}

     

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<footer class="container-fluid">

     

       
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	<div class="container">

     

       
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+
       
    <small>Developed by <a href="https://bsky.social">Bluesky Social PBC</a> for <a href="https://atproto.com">atproto</a></small>

     

       
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  </div>

     

       
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</footer>

     

       
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{% endblock -%}

     

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  <p>PLC is a method which implements the W3C Decentralized Identifier (DID) standard. This means it is interoperable and reusable by other applications and organization.</p>

     

       
12
       
 
       


     

       
13
       
-
       
  <p>Bluesky PBC developed DID PLC when designing the AT Protocol (atproto) because we were not satisfied with any of the existing DID methods. We wanted a strongly consistent, highly available, recoverable, and cryptographically secure method with fast and cheap propagation of updates.</p>

     

       
14
       
 
       


     

       
15
       
 
       
  <p>PLC stands for "Public Ledger of Credentials". The system has been in production use for several years, with over twelve million registered DIDs in the atproto network as of October 2024. We feel that the existing system provides value and is worth consideration as a persistent identifier for other applications. The system may evolve to add functionality or improve security, but will do so in a backwards-compatible manner so that existing DIDs will continue to resolve.</p>

     

       
16
       
 
       


     

···

       
10
       
 
       


     

       
11
       
 
       
  <p>PLC is a method which implements the W3C Decentralized Identifier (DID) standard. This means it is interoperable and reusable by other applications and organization.</p>

     

       
12
       
 
       


     

       
13
       
+
       
  <p>Bluesky Social PBC developed DID PLC when designing the AT Protocol (atproto) because we were not satisfied with any of the existing DID methods. We wanted a strongly consistent, highly available, recoverable, and cryptographically secure method with fast and cheap propagation of updates.</p>

     

       
14
       
 
       


     

       
15
       
 
       
  <p>PLC stands for "Public Ledger of Credentials". The system has been in production use for several years, with over twelve million registered DIDs in the atproto network as of October 2024. We feel that the existing system provides value and is worth consideration as a persistent identifier for other applications. The system may evolve to add functionality or improve security, but will do so in a backwards-compatible manner so that existing DIDs will continue to resolve.</p>

     

       
16