go-eigentrust

Go implementation of the EigenTrust algorithm. Comes with both the server and the client implementation.

Installation

Make sure Go 1.20+ is installed, e.g. using gimme:

eval $(gimme 1.20)

Then install the eigentrust binary into $GOBIN (typically $HOME/go/bin):

go install k3l.io/go-eigentrust/cmd/eigentrust@latest

Or from a local clone of this repository:

go install ./cmd/eigentrust

Try running eigentrust with no arguments:

eigentrust

If you see the help message, your $PATH is already set up correctly. If you get a command-not-found error, you need to add $GOBIN to $PATH (see Appendix > Updating $PATH at the end of this README).

Running Server

eigentrust serve

Using Compute Client CLI

This requires a running server. See the Running Server section above to run one locally.

Input

You will need local trust as well as pre-trust. Both can be specified using CSV.

Sample local trust (lt.csv):

from,to,value
ek,sd,100
vm,sd,100
ek,vm,75

Here we have 3 peers: EK, VM, and SD. Both EK and VM trust SD by 100. EK also trusts VM, by 3/4 of how much he trusts SD.

Sample pre-trust (pt.csv):

peer_id,value
ek,50
vm,100

Here, both EK and VM are pre-trusted by the network (a priori trust). VM is trusted twice as much as EK.

Running CLI

To run EigenTrust using the above input:

eigentrust basic compute -L -l lt.csv -p pt.csv

Outputs:

ek,0.21705427907166472
sd,0.3023255429103218
vm,0.4806201780180134

Here, the EigenTrust algorithm distributed the network's trust onto the 3 peers:

• EK gets 21.7%
• SD gets 30.2%
• VM gets 48.1%

Appendix

Tweaking Alpha

The pre-trust input defines the relative ratio by which the network distributes its a priori trust onto trustworthy peers, in this case EK and VM.

You can also tweak the overall absolute strength of the pre-trust. This parameter, named alpha, represents the portion of the EigenTrust output taken from the pre-trust. For example, with alpha of 0.2, the EigenTrust output is a blend of 20% pre-trust and 80% peer-to-peer trust.

The CLI default for alpha is 0.5 (50%). If you re-run EigenTrust using a lower alpha of only 0.01 (1%):

eigentrust basic compute -L -l lt.csv -p pt.csv -a 0.01

We get a different result:

ek,0.16536739107782936
sd,0.4401132971693594
vm,0.39451931175281096

EK and VM's trust shares got lower (EK 21.7% ⇒ 16.5%, VM 48.1% ⇒ 39.5%), whereas SD's trust share soared (30.2% ⇒ 44%) despite not being pre-trusted. This is because, with only 1% pre-trust level, the peer-to-peer trust opinions (where SD is trusted by both EK and VM) make up for a much larger portion of trust.

Updating $PATH

For Bourne shell compatibles (sh/bash/zsh/…), add this to ~/.profile, and restart the shell you are using for this tutorial (or run the same command in the shell directly).

PATH="${PATH+"${PATH}:"}${GOBIN:-"${GOPATH:-"${HOME}/go"}/bin"}"

For C shell and compatibles (csh/tcsh/…), add this to ~/.login, and restart the shell you are using for this tutorial (or run the same commands in the shell directly).

if (! $?GOPATH) setenv GOPATH ~/go
if (! $?GOBIN) setenv GOBIN "${GOPATH}/bin"
set path = ($path $GOBIN)