Groove

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Groove

• Preeti Mehra
• 16th November, 2001
• ECE - 579

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Groove Architecture
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• Shared Space

Mutually Trusting Shared Spaces
Mutually Suspicious Shared Spaces

• Message Received
• Re-compute MAC using LG
• Compare calc MAC with Transmitted MAC

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Why Mutually Suspicious Shared Spaces

• Corporate discussions where a lot is at risk
• Authenticated identity of a person is really
  important for discussion

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Keys used

• Keys used so far
• One passphrase per account
• One symmetric key per account
• One asymmetric key pair per identity for
  signature/Verification
• Second asymmetric key pair per identity for
  encryption / Decryption

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Keys in Mutually Suspicious Shared Spaces

• Diffie-Hellman public/private key pair
• These have to be authenticated identity key pairs
• Pairwise Symmetric keys are established
• These keys are not sent over wire. They are
  calculated individually

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Calculation of Diffie-Hellman Pairwise Keys
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Message Format in trusting Mode
Delta Header Delta Body Header Body
Digest
Group Encryption Key
Group MAC Key
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Message Format in Suspicious Mode
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Why Multi-authenticators

• Constant signature size
• Constant Time to compute signature
• Support message fan-out and recovery of lost
  messages
• Works best for small groups.

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Relay Server

• A System that understands Groove protocols
• No knowledge about members.
• Knows only about shared spaces
• Uses of relay server
• Firewall transparency
• Message fanouts
• Permits user to work offline

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Relay for message fan-outs
____ Modem Link ____ High Speed Link
A
Relay Server
B
C
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Relaying vs. Direct Connection
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Recovery of lost messages
A
B
X
C
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Recovery of lost messages
A
B
Request As Message
C
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Recovery of lost messages
A
B
Sends As Message With B/C encryption A/C MAC
C
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Invitation of people into shared spaces

• Chair - Person who sends an invitation to join a
  shared space
• Ways of inviting
• Email
• Instant Messages

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Addition of User C
A
B
Delta message of addition of C Cs DH key
C
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• By accepting, Kathleen receives Andrews public
  key
• By accepting, Kathleen sends to Andrew her public
  key
• All future instant messages and invitations are
  authenticated

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Uninvitation of a member

• A rekey delta message is sent
• Changed membership information
• piggy-backed rekey information
• new group key - transmitted by pairwise
  encrypting keys
• New piggy-backed key is used to encrypt the
  message
• Currently there is no administrative control for
  uninvitation.

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A
B
Uninvite message
C
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Rekey message sent for both trusted and not
trusted modesPer Member encryption always used
A
B
Rekey Message Group key encrypted using K (AB)
Membership Info
C
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Key Versioning Dependencies
A
B
____ Modem Link ____ High Speed Link
C
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Key Versioning Dependencies
A
B
____ Modem Link ____ High Speed Link
C
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Key Versioning Dependencies
A
B
____ Modem Link ____ High Speed Link
C
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Key Versioning Dependencies
A
B
____ Modem Link ____ High Speed Link
C
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Key Versioning Dependencies
A
B
____ Modem Link ____ High Speed Link
C
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Key Versioning Dependencies
A
B
____ Modem Link ____ High Speed Link
C
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Key Versioning Dependencies
M4
Internet
M1
M6
M5
M3
M2
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Key Versioning Dependencies
Uninvite message
M4
Internet
M1
M6
M3
M2
M5
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Addition of tools

• Any member can add new tools and functionality to
  a Groove shared space.

• When Andrew adds a CAD Viewer Tool to the shared
  space, Groove automatically tells the other
  members shared spaces to add the CAD Viewer Tool
  as well.

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• Members do not send tools to each other they
  send commands to add a tool.
• If a member already has the tool installed
  locally, Groove simply adds the tool to the
  shared space.

IT Controls
add tool
Andrew

• If a member does not already have the tool
  installed, Groove automatically locates the tool
  on a component server, downloads and installs the
  tool, and adds it to the space.
• All components are digitally signed.
• IT managers can limit which components users are
  able to download, balancing end user control and
  flexibility with corporate security guidelines.

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Enterprise Integration - multi-point Integration
www.groove.net
C
www.groove.net
B
www.groove.net
A
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Enterprise Integration - multi-point Integration
www.groove.net
C
www.groove.net
B
www.groove.net
A
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Enterprise Integration - multi-point Integration
Groove
C
Groove
B
Groove
A
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Enterprise Integration - single-point Integration
E
D
C
Data Source
BOT
A
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Enterprise Integration - single-point Integration
E
D
C
Data Source
BOT
A
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Enterprise Integration - single-point Integration
E
D
C
Data Source
BOT
A
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Building security in P2P (By IBM)

• Peer A connects to peer B announces its
  identity
• A is asked to authenticate itself
• Authentication can be done in any desired way
• B is asked to authenticate itself
• B authorizes A
• Encrypt channel to communicate

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Building security in P2P (By IBM)

• Peer AA communicates securely with C
• C communicates securely with B
• C gives A information about B (e.g. Keys)
• A initiates secure connection to B

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P2P and SSL

• JSSE - provides SSL for Java applications
• Function like regular sockets
• Transparent authentication and encryption

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Keystore - Private Key certificate containing
Public Key certificates of trusted peers. This
is protected by a password Scenario - A wants to
query resource B. But communication had to be
secure. Authentication proceeds as described
earlier
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Steps to use JSSE (Intialization)

• Prompt user for identity password
• Create home directory for that user
• Create a keystore. Secure APIs cannot do it in
  same process. Needs an external process
• Create an instance of keystore
• Create key manager to hold peers private key
• Create trust manager to hold trusted certificates
• Create SSL connection
• Create socket factories

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References

• IBMs security site
• http//www-106.ibm.com/developerworks/security/
• Groove
• http//www.groove.net
• Other interesting sites
• Intels P2P trusted library
• www.sourceforge.net/projects/ptp1
• http//www.idg.net/english/crd_peer_699186.html