Skip to content
Blockchain LabTHE VENTURE STUDIO

LibraryPrivacy2019Design paperCorpus record

Version 2 P2P Encrypted Transport Protocol

BIP 324. Dhruv Mehta, Tim Ruffing, Jonas Schnelli and Pieter Wuille.

A v2 connection does an Elligator-style handshake and then encrypts the byte stream, so a passive observer cannot read the messages or easily identify the protocol.

A reading of the public document. Not a copy of it, and not a claim about a later network that reused the name.

A privacy claim about the peer network should say whether it is this transport, a VPN, or a change to what is announced.

The five-minute read

The defect

Bitcoin's peer protocol was unencrypted. A network observer could see which transactions a node announced and which blocks it requested.

The rule

A v2 connection does an Elligator-style handshake and then encrypts the byte stream, so a passive observer cannot read the messages or easily identify the protocol.

How it is put together

The handshake is unauthenticated against an active man in the middle, unless a later authentication is added. Encryption here is against passive surveillance. The content of the chain does not become private.

Where the claim stops

This does not hide which IP you connect to.

One action, walked through

  1. Open a connection.
  2. Complete the v2 handshake.
  3. Send the same logical messages inside the encrypted stream.
  4. Is the session encrypted?

The argument, unpacked

Why it is still on the desk

A privacy claim about the peer network should say whether it is this transport, a VPN, or a change to what is announced.

After the text

Bitcoin Core shipped v2 transport as optional and then as a default direction. The BIP is the handshake.

What has to be true

  • This does not hide which IP you connect to.
  • An active attacker who intercepts the handshake can still sit in the middle.
  • It is not Tor, and not a mixnet.

What happened after the paper

Bitcoin Core shipped v2 transport as optional and then as a default direction. The BIP is the handshake.

What to check before you use the idea

  • Is the session encrypted?
  • Does the handshake authenticate the peer?
  • What can a passive observer still see?

Terms

v2 transport
The encrypted Bitcoin peer protocol.
Passive observer
A party who can read packets but not change them.

The problem the paper names

Bitcoin's peer protocol was unencrypted. A network observer could see which transactions a node announced and which blocks it requested.

What the design proposes

  • The handshake is unauthenticated against an active man in the middle, unless a later authentication is added.
  • Encryption here is against passive surveillance.
  • The content of the chain does not become private.

How the mechanism is specified

  • Open a connection.
  • Complete the v2 handshake.
  • Send the same logical messages inside the encrypted stream.

What this page does not treat as proven

  • This does not hide which IP you connect to.
  • An active attacker who intercepts the handshake can still sit in the middle.
  • It is not Tor, and not a mixnet.

Why a venture studio still reads it

A privacy claim about the peer network should say whether it is this transport, a VPN, or a change to what is announced.

This is Blockchain Lab's reading of a public design paper. It is not the paper, not a copy of it, and not an offer of tokens, equity, custody or a partnership. Later network behaviour can diverge from the text. Nothing here is investment, legal or technical advice.

Research status: Design paper. Last reviewed: 1 October 2026. This is a reading of a public paper, not investment, legal or security advice.