Google Key Transparency Tries to Succeed Where PGP Failed

Google Key Transparency Tries to Succeed Where PGP Failed

Google has launched a new toolkit for encryption key transparency designed to help developers improve messaging security.

Key Transparency, made available late last week as an open source prototype, is described as a “generic, secure way to discover a recipient's public keys for addressing messages correctly.”

Combining elements of Google’s Certificate Transparency initiative and the CONIKS key management project, this new effort was created in response to current systems like PGP, which require users to manually verify recipients’ accounts in-person.

Google security and privacy engineers, Ryan Hurst and Gary Belvin, argued in a blog post that these systems are just not practical for users.

“One of our goals with Key Transparency was to simplify this process and create infrastructure that allows making it usable by non-experts. The relationship between online personas and public keys should be automatically verifiable and publicly auditable,” they explained.

“Users should be able to see all the keys that have been attached to an account, while making any attempt to tamper with the record publicly visible. This also ensures that senders will always use the same keys that account owners are verifying.”

Key Transparency has apparently been designed over several years with input from CONIKS, Open Whisper Systems and Yahoo engineers.

“Key Transparency is a general-use, transparent directory that makes it easy for developers to create systems of all kinds with independently auditable account data,” Google added. “It can be used in a variety of scenarios where data needs to be encrypted or authenticated. It can be used to make security features that are easy for people to understand while supporting important user needs like account recovery.”

The initiative has been given a caution welcome by experts.

Cryptographer Matthew Green described it as a “fantastic” effort, and “a pretty mature piece of software that Google has designed to operate at scale.”

He added that with deployment of Key Transparency, “many of the obvious cryptographic weaknesses in secure messaging will be closed.”

However, Kevin Bocek, chief cybersecurity strategist at Venafi, said its success will depend on developer interest.

“There is not the clear compelling event as there was with Certificate Transparency, when the fraudulent issuance of digital was starting to run rampant. Moreover, building a database of public keys not linked to digital certificates has been attempted before with PGP and never gain widespread adoption,” he argued.

“Interestingly, Key Transparency continues Google’s development of blockchain alternatives like Certificate Transparency. It’s a log that is with cryptographic integrity but not blockchain. It appears Google does not believe blockchain is ready for prime time or public use.”

Source: Information Security Magazine