State Channels bi-weekly development update - End of September 2019

This is a bi-weekly update of all things concerning the protocol design and
reference implementation of State Channels. This update is delayed for about 1.5 weeks
due to the team meeting up for the developer workshop and AE Universe One Conference in Prague.

Thanks to the SC contributors @dimitar.chain, @uwiger,
@gorbak25, @aleksandar.chain and @bot.

Thanks again to the aepp developers @dave and @hernandp who have provided
invaluable feedback in respect to real-world usage of State Channels
which has led to some of the changes mentioned in this report.

Some changes which are listed below have been made towards a dedicated branch for the AE Universe One demo app.
These change are being ported to master at the moment.

The previous report was Early September 2019.

Off-chain pinned environment

Design: PR #406
Implementation: PR #2746

This change provides SC participants with the possiblitity to pin the on-chain environment
in their requests to the off-chain updates execution. It is an instrumental tool to manage risk
and ensure expectations are met when performing updates.

State cache encryption

Design: PR #396
Implementation: PR #2630, PR #2803

This change adds on-disk encryption of the state cache which prevents certain attacks on untrusted SC nodes.
While the code of the functionality is kept, the feature has been disabled for 5.0.0-rc.3 to allow an improved
version to be released as part of 5.1.0.

Making client reconnect more flexible

Implementation: PR #2785, PR #2790

The various options for re-connecting to a running channel have been consolidated to reduce
the complexity for the client and improve reliability of the implementation.

Improve and fix tests

Implementation: PR #2767, PR #2768, PR #2789, PR #2792

Various improvements to the SC integration tests and node system tests which involve SCs.

Other improvments

Implementation: PR #2757, PR #2759

Improved logging and refactoring of the aesc_offchain_update versioning.

State Channel UAT Test Suite

Implementation: PR #13, PR #14

The test suite has been heavily extended leading up to the AE Universe One Conference which helpedis
identifying protocol issues and verifying the fixes which are part of the changes described above. New changes will
involve moving towards a repeatable test setup which can be integrated into our CI.

Interesting presentations

@uwiger at the AE Universe One Conference - Scaling Off-Chain with State Channels
@dimitar.chain at the AE Universe One Conference - State Channel Client: Unleashing æpp Scalability
@hernandp and @dave at the AE Universe One Conference - Experiencing æternity’s State Channels

Interesting forum discussions

Again @dave and @hernandp have been busy in the community, now already sharing their experience and answering questions.


Thank you for the great update!