Cyber ​​security

Server Tuning

Initial server settings:

Disable root user (PermitRootLogin no)

Login via SSH only by key (PasswordAuthentication no)

Activation of Unattended Upgrades in APT

Activation of the firewall

Fail2Ban setup

Resource monitoring (Node exporter)

You can use Ansible for automation - https://bit.ly/3Bxg2b1

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Types of attacks on PoS blockchain

Sibyl (Sibyl) attack or its variation - Eclipse;

Attack +1/3;

DeFi security;

Spam transactions;

Double signature;

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Basic concepts of node security

1. Control of software used
2. Careful selection of starting nodes
3. Sentry nodes
4. Key Management Software/Hardware Security Module (KMS/HSM)
5. Horcrux (Horcrux)
6. Stable work
7. Double signature

Control of software used

Careful selection of starting nodes

If you select random nodes, the risk of establishing communication with malicious nodes increases. This applies to the seeds and persistent_peers settings.

• Careful selection of the source of the node software
• Build from source code

Sentry nodes

Used to cover the main validator node

In case of an attack on them (DDoS), they are easily replaced with new ones

Increases network delays

You can build complex node structures

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Sentry nodes. Protection options.

Validator protection options:

1. One node

The simplest and most common way.

Easy to deploy, but not very flexible

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Sentry nodes. Protection options.

2. Single layer protection

Effective protection against DDoS attacks.

If an attacker gains access to the private network, he will be able to attack the validator node.

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Sentry nodes. Protection options.

3. Double layer protection

Similar to the classic corporate scheme of separating frontend and backend

An expensive solution, and there is a bottleneck in the form of a validator node.

Stable work and double signature

The validator must make every effort to keep the node running smoothly and avoid double signing.

A double signature occurs when two different blocks at the same height are proposed by the same validator.

Penalties for downtime - 0.01% reduction of all delegated funds (soft slashing)

The penalty for double signature is 5% reduction.

KMS/HSM

To avoid double signature, a KMS/HSM solution is used.

It is designed for signing blocks on a separate node and allows you to have more than one node for validation with one key.

Disadvantages: increased cost and network delays.

https://github.com/iqlusioninc/tmkms

Horcrux

Horcrux is a signature service based on the confidential computing protocol for Tendermint nodes.

It is designed to sign blocks on individual nodes with specially generated and divided keys, which allows you to sign blocks even if some parts are missing.

When using this service, the validator's bottlenecks disappear; part of the infrastructure may be disabled, but the validator will continue to work.

https://github.com/strangelove-ventures/horcrux

https://ru.wikipedia.org/wiki/%D0%9F%D1%80%D0%BE%D1%82%D0%BE%D0%BA%D0%BE%D0%BB_%D0%BA%D0 %BE%D0%BD%D1%84%D0%B8%D0%B4%D0%B5%D0%BD%D1%86%D0%B8%D0%B0%D0%BB%D1%8C%D0%BD %D0%BE%D0%B3%D0%BE_%D0%B2%D1%8B%D1%87%D0%B8%D1%81%D0%BB%D0%B5%D0%BD%D0%B8%D1 %8F

Monitoring

Most often, the Prometheus+Grafana stack is used for monitoring.

Moreover, both Tendermint and CosmosSDK offer their own metrics for Prometheus, you just need to activate them.

https://docs.tendermint.com/master/nodes/metrics.html

https://docs.cosmos.network/master/core/telemetry.html

The main metrics that need to be monitored are: current height, number of missed blocks, current stack, voting power.

Unfortunately, not all metrics are available and sometimes you need to use your own. As an example, you can see https://monitor.bronbro.io/d/mfbuQsZn1/validator-stats?orgId=2&refresh=10s.

https://github.com/CyberObiOne/Grafana-Monitor

Questions?

Anonymous feedback

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Thank you for attention