Silencer

Zero-Knowledge Proof lib for Gunero

---

Installation and Demo

Installation

$ cd depends
$ git submodule init
$ git submodule update
$ cd libsnark/depends
$ git submodule init
$ git submodule update
$ cd ../../../
$ mkdir build
# cd build
$ cmake ..
$ make

Demo Instructions

1. Generate proving and verifying keys for all circuits

$ cd demo
$ ../silencer generate --circuit=authorization \
        --proving-key-output=./authorization-pk.json \
        --verifying-key-output=./authorization-vk.json
$ ../silencer generate --circuit=receive \
        --proving-key-output=./receive-pk.json \
        --verifying-key-output=./receive-vk.json
$ ../silencer generate --circuit=spend \
        --proving-key-output=./spend-pk.json \
        --verifying-key-output=./spend-vk.json

2. Create a firearm token and previous transaction

$ echo [PICK RANDOM NUMBER] > ./firearm.rand
$ echo [PICK RANDOM SERIAL] > ./firearm.serial
$ python gen-token.py \
        $(cat ./firearm.rand) \
        $(cat ./firearm.serial) \
        > ./token.hash
$ echo [PICK RANDOM ACCOUNT] > ./previous.acct
$ python gen-txn-hash.py \
        $(cat ./previous.acct) \
        $(cat ./sender.key) \
        $(cat ./token.hash) \
        $(cat ./auth-root.hash) \
        > ./previous-transaction.hash

3. Generate authorization proof for both accounts

$ echo [PICK RANDOM NUMBER] > ./sender-view.rand
$ python gen-view-hash.py \
        $(cat ./sender.acct) \
        $(cat ./auth-root.hash) \
        $(cat ./sender-view.rand) \
        > ./sender-view.hash
$ ../silencer prove --circuit=authorization \
        --proving-key=./authorization-pk.json \
        --auth-root-hash=./auth-root.hash \
        --account-status=1 \
        --account-view-hash=./sender-view.hash \
        --account-private-key=./sender.key \
        --account-view-randomizer=./sender-view.rand \
        --auth-sender-branch=./sender-branch.ls \
        --output=./sender-auth.proof

Note: Repeat above steps for receiver

4. Receiver generates transaction hash

$ python gen-txn-hash.py \
        $(cat ./sender.acct) \
        $(cat ./receiver.key) \
        $(cat ./token.hash) \
        $(cat ./auth-root.hash) \
        > ./transaction.hash

5. Generate the receiver proof with receiver's account

$ ../silencer prove --circuit=receive \
        --proving-key=./receive-pk.json \
        --auth-root-hash=./auth-root.hash \
        --token=./token.hash \
        --receiver-view-hash=./receiver-view.hash \
        --sender-view-hash=./sender-view.hash \
        --transaction-hash=./transaction.hash \
        --receiver-private-key=./receiver.key \
        --receiver-view-randomizer=./receiver-view.rand \
        --sender-account=./sender.acct \
        --sender-view-randomizer=./sender-view.rand \
        --firearm-serial=./firearm.serial \
        --firearm-view-randomizer=./firearm.rand \
        --output=./receive.proof

6. Generate the spend proof with the sender's acocunt

$ ../silencer prove --circuit=spend \
        --proving-key=./spend-pk.json \
        --auth-root-hash=./auth-root.hash \
        --token=./token.hash \
        --receiver-view-hash=./receiver-view.hash \
        --sender-view-hash=./sender-view.hash \
        --previous-transaction-hash=./previous-transaction.hash \
        --sender-private-key=./receiver.key \
        --sender-view-randomizer=./sender-view.rand \
        --receiver-view-randomizer=./receiver-view.rand \
        --previous-account=./previous.acct \
        --previous-auth-root-hash=./auth-root.hash
        --output=./spend.proof

7. Validate all the proofs

$ ../silencer verify --circuit=authorization \
        --verifying-key=./authorization-vk.json \
        --auth-root-hash=./auth-root.hash \
        --account-status=1 \
        --account-view-hash=./sender-view.hash \
        --proof=./sender-auth.proof
SUCCESS!
$ ../silencer verify --circuit=authorization \
        --verifying-key=./authorization-vk.json \
        --auth-root-hash=./auth-root.hash \
        --account-status=1 \
        --account-view-hash=./receiver-view.hash \
        --proof=./receiver-auth.proof
SUCCESS!
$ ../silencer verify --circuit=receive \
        --proving-key=./receive-vk.json \
        --auth-root-hash=./auth-root.hash \
        --token=./token.hash \
        --receiver-view-hash=./receiver-view.hash \
        --sender-view-hash=./sender-view.hash \
        --transaction-hash=./transaction.hash \
        --proof=./receive.proof
SUCCESS!
$ ../silencer verify --circuit=spend \
        --proving-key=./spend-vk.json \
        --auth-root-hash=./auth-root.hash \
        --token=./token.hash \
        --receiver-view-hash=./receiver-view.hash \
        --sender-view-hash=./sender-view.hash \
        --previous-transaction-hash=./previous-transaction.hash \
        --proof=./spend.proof
SUCCESS!

NOTE: Yes, the proofs do indeed fail if not consistent:

$ ../silencer verify --circuit=authorization \
        --verifying-key=./authorization-vk.json \
        --auth-root-hash=./auth-root.hash \
        --account-status=1 \
        --account-view-hash=./receiver-view.hash \
        --proof=./sender-auth.proof
FAIL!
$ ../silencer verify --circuit=authorization \
        --verifying-key=./authorization-vk.json \
        --auth-root-hash=./auth-root.hash \
        --account-status=1 \
        --account-view-hash=./sender-view.hash \
        --proof=./receiver-auth.proof
FAIL!