README
¶
Metadata absolutely tells you everything about somebody's life
— Stewart Baker, former General Counsel of the NSA
|
We kill people based on metadata
— Michael Hayden, former Director of the NSA
Vuvuzela
Vuvuzela is a messaging system that protects the privacy of message contents and message metadata. Users communicating through Vuvuzela do not reveal who they are talking to, even in the presence of powerful nation-state adversaries. Our SOSP 2015 paper explains the system, its threat model, performance, limitations, and more. Our SOSP 2015 slides give a more graphical overview of the system.
Vuvuzela is the first system that provides strong metadata privacy while scaling to millions of users. Previous systems that hide metadata using Tor (such as Pond) are prone to traffic analysis attacks. Systems that encrypt metadata using techniques like DC-nets and PIR don't scale beyond thousands of users.
Vuvuzela uses efficient cryptography (NaCl) to hide as much metadata as possible and adds noise to metadata that can't be encrypted efficiently. This approach provides less privacy than encrypting all of the metadata, but it enables Vuvuzela to support millions of users. Nonetheless, Vuvuzela adds enough noise to thwart adversaries like the NSA and guarantees differential privacy for users' metadata.
Screenshots
A conversation in the Vuvuzela client
In practice, the message latency would be around 20s to 40s, depending on security parameters and the number of users connected to the system.
Noise generated by the Vuvuzela servers
Vuvuzela is unable to encrypt two kinds of metadata: the number of idle users (connected users without a conversation partner) and the number of active users (users engaged in a conversation). Without noise, a sophisticated adversary could use this metadata to learn who is talking to who. However, the Vuvuzela servers generate noise that perturbs this metadata so that it is difficult to exploit.
Usage
Follow these steps to run the Vuvuzela system locally using the provided sample configs.
-
Install Vuvuzela (assuming
GOPATH=~/go
, requires Go 1.4 or later):$ go get github.com/davidlazar/vuvuzela/...
The remaining steps assume PATH
contains ~/go/bin
and that the
current working directory is ~/go/src/github.com/davidlazar/vuvuzela
.
-
Start the last Vuvuzela server:
$ vuvuzela-server -conf confs/local-last.conf
-
Start the middle server (in a new shell):
$ vuvuzela-server -conf confs/local-middle.conf
-
Start the first server (in a new shell):
$ vuvuzela-server -conf confs/local-first.conf
-
Start the entry server (in a new shell):
$ vuvuzela-entry-server -wait 1s
-
Run the Vuvuzela client:
$ vuvuzela-client -conf confs/alice.conf
The client supports these commands:
/dial <user>
to dial another user/talk <user>
to start a conversation/talk <yourself>
to end a conversation
Deployment considerations
This Vuvuzela implementation is not ready for wide-use deployment. In particular, we haven't yet implemented these crucial components:
-
Public Key Infrastructure: Vuvuzela assumes the existence of a PKI in which users can privately learn each others public keys. This implementation uses
pki.conf
as a placeholder until we integrate a real PKI. -
CDN to distribute dialing dead drops: Vuvuzela's dialing protocol (used to initiate conversations) uses a lot of server bandwidth. To make dialing practical, Vuvuzela should use a CDN or BitTorrent to distribute the dialing dead drops.
There is a lot more interesting work to do. See the issue tracker for more information.
Acknowledgements
This code is written by David Lazar with contributions from Jelle van den Hooff, Nickolai Zeldovich, and Matei Zaharia.
Documentation
¶
Overview ¶
Types used by the entry server and client
Index ¶
- Constants
- func BackwardNonce(round uint32) *[24]byte
- func FillWithFakeDoubles(dest [][]byte, nonce *[24]byte, nextKeys []*[32]byte)
- func FillWithFakeIntroductions(dest [][]byte, noiseCounts []int, nonce *[24]byte, nextKeys []*[32]byte)
- func FillWithFakeSingles(dest [][]byte, nonce *[24]byte, nextKeys []*[32]byte)
- func ForwardNonce(round uint32) *[24]byte
- func InitConvoService(srv *ConvoService)
- func InitDialService(srv *DialService)
- func Intn(rand io.Reader, n int) int
- func KeyDialBucket(key *BoxKey, buckets uint32) uint32
- func NewConvoRound(client *vrpc.Client, round uint32) error
- func NewDialRound(client *vrpc.Client, round uint32) error
- func RunConvoRound(client *vrpc.Client, round uint32, onions [][]byte) ([][]byte, error)
- func RunDialRound(client *vrpc.Client, round uint32, onions [][]byte) error
- type AccessCount
- type AnnounceConvoRound
- type AnnounceDialRound
- type BadRequestError
- type BoxKey
- type BoxKeys
- type ConvoAddArgs
- type ConvoError
- type ConvoExchange
- type ConvoGetArgs
- type ConvoGetResult
- type ConvoOpenArgs
- type ConvoRequest
- type ConvoResponse
- type ConvoRound
- type ConvoService
- func (srv *ConvoService) Add(args *ConvoAddArgs, _ *struct{}) error
- func (srv *ConvoService) Close(Round uint32, _ *struct{}) error
- func (srv *ConvoService) Delete(Round uint32, _ *struct{}) error
- func (srv *ConvoService) Get(args *ConvoGetArgs, result *ConvoGetResult) error
- func (srv *ConvoService) NewRound(Round uint32, _ *struct{}) error
- func (srv *ConvoService) Open(args *ConvoOpenArgs, _ *struct{}) error
- type DeadDrop
- type DialAddArgs
- type DialBucket
- type DialBucketsArgs
- type DialBucketsResult
- type DialError
- type DialExchange
- type DialRequest
- type DialRound
- type DialService
- type Envelope
- type Introduction
- type MsgType
- type PKI
- func (pki *PKI) FirstServer() string
- func (pki *PKI) IncomingOnionOverhead(serverName string) int
- func (pki *PKI) Index(serverName string) int
- func (pki *PKI) LastServer() string
- func (pki *PKI) NextServer(serverName string) string
- func (pki *PKI) NextServerKeys(serverName string) BoxKeys
- func (pki *PKI) OutgoingOnionOverhead(serverName string) int
- func (pki *PKI) ServerKeys() BoxKeys
- type ServerInfo
- type Shuffler
Constants ¶
const ( SizeMessage = 240 // Eventually this might be dynamic, but one bucket is usually // sufficient if users don't dial very often. TotalDialBuckets = 1 DialWait = 10 * time.Second DefaultReceiveWait = 5 * time.Second DefaultServerAddr = ":2718" DefaultServerPort = "2718" )
const ( SizeEncryptedMessage = SizeMessage + box.Overhead SizeConvoExchange = int(unsafe.Sizeof(ConvoExchange{})) SizeEncryptedIntro = int(unsafe.Sizeof(Introduction{})) + onionbox.Overhead SizeDialExchange = int(unsafe.Sizeof(DialExchange{})) )
Variables ¶
This section is empty.
Functions ¶
func BackwardNonce ¶
func FillWithFakeDoubles ¶
func FillWithFakeSingles ¶
func ForwardNonce ¶
func InitConvoService ¶
func InitConvoService(srv *ConvoService)
func InitDialService ¶
func InitDialService(srv *DialService)
func KeyDialBucket ¶
func RunConvoRound ¶
Types ¶
type AccessCount ¶
type AnnounceConvoRound ¶
type AnnounceConvoRound struct {
Round uint32
}
type AnnounceDialRound ¶
type BadRequestError ¶
type BadRequestError struct {
Err string
}
func (*BadRequestError) Error ¶
func (e *BadRequestError) Error() string
type BoxKey ¶
type BoxKey [32]byte
func GenerateBoxKey ¶
func KeyFromString ¶
func (*BoxKey) MarshalJSON ¶
func (*BoxKey) UnmarshalJSON ¶
type ConvoAddArgs ¶
type ConvoError ¶
func (*ConvoError) Error ¶
func (e *ConvoError) Error() string
type ConvoExchange ¶
type ConvoExchange struct { DeadDrop DeadDrop EncryptedMessage [SizeEncryptedMessage]byte }
func (*ConvoExchange) Marshal ¶
func (e *ConvoExchange) Marshal() []byte
func (*ConvoExchange) Unmarshal ¶
func (e *ConvoExchange) Unmarshal(data []byte) error
type ConvoGetArgs ¶
type ConvoGetResult ¶
type ConvoGetResult struct {
Onions [][]byte
}
type ConvoOpenArgs ¶
type ConvoRequest ¶
type ConvoResponse ¶
type ConvoRound ¶
type ConvoRound struct {
// contains filtered or unexported fields
}
type ConvoService ¶
type ConvoService struct { Idle *sync.Mutex LaplaceMu float64 LaplaceB float64 PKI *PKI ServerName string PrivateKey *BoxKey Client *vrpc.Client LastServer bool AccessCounts chan *AccessCount // contains filtered or unexported fields }
func (*ConvoService) Add ¶
func (srv *ConvoService) Add(args *ConvoAddArgs, _ *struct{}) error
func (*ConvoService) Close ¶
func (srv *ConvoService) Close(Round uint32, _ *struct{}) error
func (*ConvoService) Delete ¶
func (srv *ConvoService) Delete(Round uint32, _ *struct{}) error
func (*ConvoService) Get ¶
func (srv *ConvoService) Get(args *ConvoGetArgs, result *ConvoGetResult) error
func (*ConvoService) NewRound ¶
func (srv *ConvoService) NewRound(Round uint32, _ *struct{}) error
func (*ConvoService) Open ¶
func (srv *ConvoService) Open(args *ConvoOpenArgs, _ *struct{}) error
type DialAddArgs ¶
type DialBucket ¶
type DialBucket struct { Round uint32 Intros [][SizeEncryptedIntro]byte }
type DialBucketsArgs ¶
type DialBucketsArgs struct {
Round uint32
}
type DialBucketsResult ¶
type DialBucketsResult struct {
Buckets [][][SizeEncryptedIntro]byte
}
type DialExchange ¶
type DialExchange struct { Bucket uint32 EncryptedIntro [SizeEncryptedIntro]byte }
func (*DialExchange) Marshal ¶
func (e *DialExchange) Marshal() []byte
func (*DialExchange) Unmarshal ¶
func (e *DialExchange) Unmarshal(data []byte) error
type DialRequest ¶
type DialService ¶
type DialService struct { Idle *sync.Mutex LaplaceMu float64 LaplaceB float64 PKI *PKI ServerName string PrivateKey *BoxKey Client *vrpc.Client LastServer bool // contains filtered or unexported fields }
func (*DialService) Add ¶
func (srv *DialService) Add(args *DialAddArgs, _ *struct{}) error
func (*DialService) Buckets ¶
func (srv *DialService) Buckets(args *DialBucketsArgs, result *DialBucketsResult) error
func (*DialService) Close ¶
func (srv *DialService) Close(Round uint32, _ *struct{}) error
func (*DialService) NewRound ¶
func (srv *DialService) NewRound(Round uint32, _ *struct{}) error
type Envelope ¶
type Envelope struct { Type MsgType Message json.RawMessage }
type Introduction ¶
func (*Introduction) Marshal ¶
func (i *Introduction) Marshal() []byte
func (*Introduction) Unmarshal ¶
func (i *Introduction) Unmarshal(data []byte) error
type PKI ¶
type PKI struct { People map[string]*BoxKey Servers map[string]*ServerInfo ServerOrder []string EntryServer string }
func (*PKI) FirstServer ¶
func (*PKI) IncomingOnionOverhead ¶
func (*PKI) LastServer ¶
func (*PKI) NextServer ¶
func (*PKI) NextServerKeys ¶
func (*PKI) OutgoingOnionOverhead ¶
func (*PKI) ServerKeys ¶
type ServerInfo ¶
Source Files
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Directories
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Path | Synopsis |
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parallelfor.go by Jelle van den Hooff
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parallelfor.go by Jelle van den Hooff |