[Caml-list] Blockchains in OCaml

[Caml-list] Blockchains in OCaml

[Arthur Breitman]

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Since blockchains tend to be a hot topic these days*, I am pleased to
announce that OCaml is also present in this domain with the Tezos project.

Tezos is a cryptographic ledger (in the same vein as Bitcoin or Ethereum)
written from scratch entirely in OCaml, in partnership with OCamlPro.

We are lucky to rely on some great OCaml libraries like Irmin and Lwt, and
have contributed some libraries of our own like ocplib-json-typed (for
reliable manipulation of JSON values) and ocplib-resto (for type safe HTTP/JSON
RPCs).

Tezos is a self-amending ledger. While other protocols achieve consensus
about the state of their transactions, Tezos reaches a meta-consensus about
its own protocol. This allows us to gradually build governance rules into
the ledger by letting the participants choose under which condition the
protocol may be amended.

We start with a simple voting procedure to accept or reject a proposed
patch to a set of OCaml modules representing the protocol. Over time,
complex rules can evolve. For instance, we may introduce a form of
constitutionalism by having the protocol require and enforce that any
proposed modification be formally verified and guaranteed to preserve
specific properties.

If you find this intriguing and enjoy working in OCaml, please reach out:
we're hiring! If you lean on the academic side and have experience with
formal verification, reach out as well! We'd be interested in proving the
correctness of some aspects of the protocol or sponsoring research in the
field in general (within our modest means).

Best,
Arthur

* perhaps hotter than it ought to be but, past the hype, there remains
susbtance

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Re: [Caml-list] Blockchains in OCaml

[Van Chan Ngo]

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Hi Arthur,

It is interesting to implement blockchains in functional language like OCaml. I am happy to hear more about this project.

FYI, a related work, we are in progress to formalize the Ethereum Virtual Machine (EVM, the running environment of smart contracts) in Coq.

Best,
-Chan


> On Oct 5, 2016, at 11:59 PM, Arthur Breitman <arthurb@tezos.com> wrote:
> 
> If you find this intriguing and enjoy working in OCaml, please reach out: we're hiring! If you lean on the academic side and have experience with formal verification, reach out as well! We'd be interested in proving the correctness of some aspects of the protocol or sponsoring research in the field in general (within our modest means).
> 


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Re: [Caml-list] Blockchains in OCaml

[Viet Le]

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Hi all,

Only one year after this message, I found interest in building a blockchain
and smart contracts in OCaml. May I know how far is the EVM formalisation
in Coq?

There aren't many materials / blockchain implementations in OCaml but I
found some interesting links:

https://github.com/LaurentMazare/btc-ocaml

http://www.liquidity-lang.org/

https://github.com/tezos/tezos

https://github.com/pirapira/eth-isabelle

https://github.com/pirapira/ethereum-formal-verification-overview

I would like to know more if anyone has more information.

Thanks,
Viet

On 10 October 2016 at 15:00, Van Chan Ngo <chan.ngo2203@gmail.com> wrote:

> Hi Arthur,
>
> It is interesting to implement blockchains in functional language like
> OCaml. I am happy to hear more about this project.
>
> FYI, a related work, we are in progress to formalize the Ethereum Virtual
> Machine (EVM, the running environment of smart contracts) in Coq.
>
> Best,
> -Chan
>
>
> On Oct 5, 2016, at 11:59 PM, Arthur Breitman <arthurb@tezos.com> wrote:
>
> If you find this intriguing and enjoy working in OCaml, please reach out:
> we're hiring! If you lean on the academic side and have experience with
> formal verification, reach out as well! We'd be interested in proving the
> correctness of some aspects of the protocol or sponsoring research in the
> field in general (within our modest means).
>
>
>


-- 
Kind regards,
Viet

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Re: [Caml-list] Blockchains in OCaml

[Van Chan Ngo]

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Hi Viet,

I did not work on the formalization of EVM a while ago due to other work
(automatic resource bound analysis for probabilistic programs
https://channgo2203.github.io/pdfs/cmutr02.pdf)
The following is the implementation (not completed) on Github.
https://github.com/channgo2203/fevm

However, we are working on the other aspect of EVM code analysis. We want
to statically infer an upper-bound on the amount of gas
consumption for all inputs (input arguments and storage configurations).
This analysis is based on our previous research on resource bound
analysis for both imperative and functional programs.

We translate EVM byte-code into a kind of control flow graph (CFG).
However, due to the unstructured and low level of EVM, I suppose it is
more convenient to infer upper-bound on gas consumption at Solidity source
code provided that we have a good gas consumption model for
Solidity language constructs.

Best,
-Van Chan




On Mon, Dec 25, 2017 at 8:28 AM, Viet Le <vietlq85@gmail.com> wrote:

> Hi all,
>
> Only one year after this message, I found interest in building a
> blockchain and smart contracts in OCaml. May I know how far is the EVM
> formalisation in Coq?
>
> There aren't many materials / blockchain implementations in OCaml but I
> found some interesting links:
>
> https://github.com/LaurentMazare/btc-ocaml
>
> http://www.liquidity-lang.org/
>
> https://github.com/tezos/tezos
>
> https://github.com/pirapira/eth-isabelle
>
> https://github.com/pirapira/ethereum-formal-verification-overview
>
> I would like to know more if anyone has more information.
>
> Thanks,
> Viet
>
> On 10 October 2016 at 15:00, Van Chan Ngo <chan.ngo2203@gmail.com> wrote:
>
>> Hi Arthur,
>>
>> It is interesting to implement blockchains in functional language like
>> OCaml. I am happy to hear more about this project.
>>
>> FYI, a related work, we are in progress to formalize the Ethereum Virtual
>> Machine (EVM, the running environment of smart contracts) in Coq.
>>
>> Best,
>> -Chan
>>
>>
>> On Oct 5, 2016, at 11:59 PM, Arthur Breitman <arthurb@tezos.com> wrote:
>>
>> If you find this intriguing and enjoy working in OCaml, please reach out:
>> we're hiring! If you lean on the academic side and have experience with
>> formal verification, reach out as well! We'd be interested in proving the
>> correctness of some aspects of the protocol or sponsoring research in the
>> field in general (within our modest means).
>>
>>
>>
>
>
> --
> Kind regards,
> Viet
>

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Re: [Caml-list] Blockchains in OCaml

[Viet Le]

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Thanks Van Chan for sharing.

I also found a solution that automatically computes the gas used by
breaking down into basic computations. They are Zen Protocol:
https://www.zenprotocol.com . They use F* that is very closely related to
OCaml/F# to achieve their goal. So if you want to find upper-bound for EVM,
I think their whitepaper is a good start.

Regards,
Viet

On 26 December 2017 at 14:03, Van Chan Ngo <chan.ngo2203@gmail.com> wrote:

> Hi Viet,
>
> I did not work on the formalization of EVM a while ago due to other work
> (automatic resource bound analysis for probabilistic programs
> https://channgo2203.github.io/pdfs/cmutr02.pdf)
> The following is the implementation (not completed) on Github.
> https://github.com/channgo2203/fevm
>
> However, we are working on the other aspect of EVM code analysis. We want
> to statically infer an upper-bound on the amount of gas
> consumption for all inputs (input arguments and storage configurations).
> This analysis is based on our previous research on resource bound
> analysis for both imperative and functional programs.
>
> We translate EVM byte-code into a kind of control flow graph (CFG).
> However, due to the unstructured and low level of EVM, I suppose it is
> more convenient to infer upper-bound on gas consumption at Solidity source
> code provided that we have a good gas consumption model for
> Solidity language constructs.
>
> Best,
> -Van Chan
>
>
>
>
> On Mon, Dec 25, 2017 at 8:28 AM, Viet Le <vietlq85@gmail.com> wrote:
>
>> Hi all,
>>
>> Only one year after this message, I found interest in building a
>> blockchain and smart contracts in OCaml. May I know how far is the EVM
>> formalisation in Coq?
>>
>> There aren't many materials / blockchain implementations in OCaml but I
>> found some interesting links:
>>
>> https://github.com/LaurentMazare/btc-ocaml
>>
>> http://www.liquidity-lang.org/
>>
>> https://github.com/tezos/tezos
>>
>> https://github.com/pirapira/eth-isabelle
>>
>> https://github.com/pirapira/ethereum-formal-verification-overview
>>
>> I would like to know more if anyone has more information.
>>
>> Thanks,
>> Viet
>>
>> On 10 October 2016 at 15:00, Van Chan Ngo <chan.ngo2203@gmail.com> wrote:
>>
>>> Hi Arthur,
>>>
>>> It is interesting to implement blockchains in functional language like
>>> OCaml. I am happy to hear more about this project.
>>>
>>> FYI, a related work, we are in progress to formalize the Ethereum
>>> Virtual Machine (EVM, the running environment of smart contracts) in Coq.
>>>
>>> Best,
>>> -Chan
>>>
>>>
>>> On Oct 5, 2016, at 11:59 PM, Arthur Breitman <arthurb@tezos.com> wrote:
>>>
>>> If you find this intriguing and enjoy working in OCaml, please reach
>>> out: we're hiring! If you lean on the academic side and have experience
>>> with formal verification, reach out as well! We'd be interested in proving
>>> the correctness of some aspects of the protocol or sponsoring research in
>>> the field in general (within our modest means).
>>>
>>>
>>>
>>
>>
>> --
>> Kind regards,
>> Viet
>>
>
>


-- 
Kind regards,
Viet

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Re: [Caml-list] Blockchains in OCaml

[Fabrice Le Fessant]

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On Mon, Dec 25, 2017 at 2:28 PM Viet Le <vietlq85@gmail.com> wrote:

> There aren't many materials / blockchain implementations in OCaml but I
> found some interesting links:
> [...]
> http://www.liquidity-lang.org/
> [...]
>

OCamlPro is doing a lot of work on blockchains these days. There is indeed
Liquidity, a smart-contract language for Tezos that we already released on
Github. We are also developing some tooling around Ethereum, we will
probably release some parts as libraries, when they become mature enough.

Fabrice

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