Key Transparency

Key Transparency provides a lookup service for generic records and a public, tamper-proof audit log of all record changes. While being publicly auditable, individual records are only revealed in response to queries for specific IDs.

Key Transparency can be used as a public key discovery service to authenticate users and provides a mechanism to keep the service accountable. It can be used by account owners to reliably see what keys have been associated with their account, and it can be used by senders to see how long an account has been active and stable before trusting it.

• Overview
• Design document
• API

Key Transparency is inspired by CONIKS and Certificate Transparency. It is a work-in-progress with the following milestones under development.

Key Transparency Client

Setup

1. Install Go 1.7.
2. go get -u github.com/google/keytransparency/cmd/keytransparency-client
3. Get an OAuth client ID and download the generated JSON file to client_secret.json.

Client operations

Publish a public key

keytransparency-client authorized-keys --help 
keytransparency-client authorized-keys add --generate --type=ecdsa --activate
keytransparency-client post user@domain.com app1 --client-secret=client_secret.json --insecure -d 'dGVzdA==' #Base64

Get and verify a public key

keytransparency-client get <email> <app> --insecure --verbose
✓ Commitment verified.
✓ VRF verified.
✓ Sparse tree proof verified.
✓ Signed Map Head signature verified.
CT ✓ STH signature verified.
CT ✓ Consistency proof verified.
CT   New trusted STH: 2016-09-12 15:31:19.547 -0700 PDT
CT ✓ SCT signature verified. Saving SCT for future inclusion proof verification.
✓ Signed Map Head CT inclusion proof verified.
keys:<key:"app1" value:"test" >

Verify key history

keytransparency-client history <email> --insecure
Epoch |Timestamp                    |Profile
4     |Mon Sep 12 22:23:54 UTC 2016 |keys:<key:"app1" value:"test" >

Running the server

Install

1. OpenSSL
2. Docker
   • Docker Engine 1.13.0+ docker version -f '{{.Server.APIVersion}}'
   • Docker Compose 1.11.0+ docker-compose --version
3. go get -u github.com/google/keytransparency/...
4. go get -u github.com/google/trillian/...
5. ./scripts/prepare_server.sh -f

Run

1. Start Trillian

$ docker-compose up -d trillian-map trillian-log
Creating keytransparency_db_1
Creating  keytransparency_trillian-map_1
Creating  keytransparency_trillian-log_1

2. Provision a log and a map

source scripts/configure_trillian.sh && createLog && createMap

3. Run Key Transparency

• docker-compose up -d
• docker-compose logs --tail=0 --follow
• https://localhost:8080/v1/users/foo@bar.com?app_id=app1
• https://localhost:8080/v1/domain/info
• Prometheus graphs