Ring signatures and ring confidential transactions (RingCT) help provide privacy and security in Monero transactions. Transactions include dummy outputs which make it difficult to determine real inputs and outputs, providing privacy. Stealth addresses further obscure sender and recipient identities. Monero aims to provide untraceable and private transactions by default through these techniques.

1. SECURE. PRIVATE. UNTRACEABLE.
Oslo, Norway

2. Welcome
Justin Ehrenhofer
Finance
Management Information Systems
/u/SamsungGalaxyPlayer or sgp_
CryptoUMN.com

3. A History of Decentralized Systems

4. People Started Adding Tools to Bitcoin

5. People Started Adding Tools to Bitcoin

6. People Started Adding Tools to Bitcoin

7. The Monero Difference
SENDER RECEIVER
RING
SIGNATURES
STEALTH
ADDRESSES
AMOUNT TRANSACTION
BROADCAST
ɱ
KOVRI
(I2P ROUTER)
RING CONFIDENTIAL
TRANSACTIONS (RINGCT)

8. Ring Signatures & RingCT
8 (Tx ID hng6iwfumwf8)
9 (Tx ID cb8vqfi8dfj65f)
1 (Tx ID e4hn4ifqyd5ed)
3 (Tx ID wb4f5hdfdicnd)
4 (Tx ID nh5nogsefwjw)
6 (Tx ID ybwnng8nengf)
2 (Tx ID eshgni5lsvnf74)
5 (Tx ID fgwinw3fwtk54)
7 (Tx ID e4bgn8flwwrj8)
10 (Tx ID fnidmfnu3dm8)
11 (Tx ID twv8mf8dnfas)
13 (Tx ID 7nr8mrjffijdtm)
12 (Tx ID h5o8mfdngkd)
14 (Tx ID f8n8madkrjmd)
15 (Tx ID wn3f4diiijffwn)
16 (Tx ID 5 f8wnfdmmii)
17 (Tx ID h8fn5mdfi4w)
18 (Tx ID n48gfwmfdki)
20 (Tx ID t4vn8lf8djer4)
19 (Tx ID fnidmnfdsam)
21 (Tx ID 4f5f8njdoam4)
BLOCKCHAIN
8 (Tx ID hng6iwfumwf8)
5 (Tx ID fgwinw3fwtk54)
11 (Tx ID twv8mf8dnfas)
15 (Tx ID wn3f4diiijffwn)
18 (Tx ID n48gfwmfdki)
21 (Tx ID 4f5f8njdoam4)

9. Ring Signatures & RingCT
Ringsize=6
INPUTSMinimumSeptember2017*
MinimumToday
5 (Tx ID fgwinw3fwtk54)
8 (Tx ID hng6iwfumwf8)
11 (Tx ID twv8mf8dnfas)
15 (Tx ID wn3f4diiijffwn)
18 (Tx ID n48gfwmfdki)
21 (Tx ID 4f5f8njdoam4) key image

10. 5 (Tx ID fgwinw3fwtk54)5 (Tx ID fgwinw3fwtk54)
8 (Tx ID hng6iwfumwf8)
11 (Tx ID twv8mf8dnfas)
15 (Tx ID wn3f4diiijffwn)
18 (Tx ID n48gfwmfdki)
21 (Tx ID 4f5f8njdoam4)
Ring Signatures & RingCT
Ringsize=6
INPUTSMinimumSeptember2017*
MinimumToday
8 (Tx ID hng6iwfumwf8)
11 (Tx ID twv8mf8dnfas)
15 (Tx ID wn3f4diiijffwn)
18 (Tx ID n48gfwmfdki)
21 (Tx ID 4f5f8njdoam4) key image
RingCT ring signature,
signs difference
between commitments
? XMR
Pedersen commitment
rCT = x*G + a*H(G)
Commitment
public key
Random Number Actual Amount

11. Ring Signatures & RingCT
5
8
11
15
18
21
INPUTS
NewerOlder
Coinbase Transaction
(New Money)
Input Actually
Spent
Someone Else
Borrowed Input

12. How Inputs Are Selected
AT LAUNCH
CURRENT (IMPROVED TRIANGULAR DISTRIBUTION)
IDEAL
ENTIRE BLOCKCHAIN
Time Since Last Spent

13. ORIGIN
NODE
12.154.85.166
LOGGING
NODE
Tx ID: 375wd4h

14. ORIGIN
NODE
3dsnf28.i2p
LOGGING
NODE
Tx ID: 375wd4h

15. Stealth Addresses
OUTPUTS
? XMR
Back to Sender
To Receiver
INPUTS
100 XMR
OR
hfk5yndjdmnfirwm5dnu
7yf8dji8fbwb4f5hdfdicnd
ey5f8ne58nh5nogsefwjw
58fmd8jhybwnng8nengf
5hfnq835hng6iwfumwf8
3348dqnqcb8vqfi8dfj65f
Commitment public key

16. Summary
5 (Tx ID fgwinw3fwtk54)
8 (Tx ID hng6iwfumwf8)
11 (Tx ID twv8mf8dnfas)
15 (Tx ID wn3f4diiijffwn)
18 (Tx ID n48gfwmfdki)
21 (Tx ID 4f5f8njdoam4)
? XMR
hfk5yndjdmnfirwm5dnu
7yf8dji8fbwb4f5hdfdicnd
ey5f8ne58nh5nogsefwjw
58fmd8jhybwnng8nengf
5hfnq835hng6iwfumwf8
3348dqnqcb8vqfi8dfj65f
Commitment public key

17. Mandatory Privacy
Source: MoneroBlocks.info 24 Feb 2016
Source: zcha.in 15 March 2017

18. A Brief History
Adapted from Scott Anecito’s Presentation

19. The Infamous GUI

20. MyMonero Lightweight Wallet

21. Regulatory Compliance and Transparency
A view key is used to
reveal all transactions for
a Monero account, or just
the key for a single
transaction
Transparency
View keys can be given to
selected parties, or can be
made public
Selected Parties
By publishing their view
key, charities can invite
easy public oversight
Charities
Children can be given
their own accounts, and
parents can monitor their
spending
Parents
(with the View Key)
Adapted from Riccardo Spagni’s Presentation

22. Monero Limitations
…but so close!
- Coinomi
- GUI port
- MyMonero
- Jaxx

23. Ongoing Development
Multisig Sub-Addresses Translations
Lightweight
Wallet
RingCT
Optimizations
Community

24. Hardfork Schedule
September 18th*
• Mandatory RingCT
• Minimum ringsize ≥5 (likely 10)
• Fluffy blocks (in testing now)
• Improved input selection algorithm
• 0MQ
• Sub-Addresses
January April September

25. Community Growth

26. Community Growth

27. XMR.TO – Pay Bitcoin Addresses with Monero

28. Thank You!
monero.stackexchange.com
getmonero.org
/r/Monero
justin@ehrenhofer.org