This document discusses Masked Authenticated Messaging (MAM) on IOTA. MAM allows for the creation of encrypted and authenticated message channels using Merkle trees. Key aspects covered include the MAM object structure, different channel modes (public, private, restricted), and how messages are attached to the Tangle through MAM bundles containing a MAM section and signature section.

1. MASKED AUTHENTICATED MESSAGE
Junwei

3. Transaction Address ?

4. 20°C
21°C
21°C
?? ?

5. ?? ?

6. Transaction Address ?

7. 20°C
21°C
21°C
4°C
7°C
5°C
20°C 4°C 21°C 7°C 21°C 5°C

9. IOTA MAM ?

10. •
• root side_key
• Seed
•
•
MAM Summary
MAM

11. MAM Channel
Message Chain
Youtube

12. Message chain
MAM

13. Data = 20°C
Message 0
Address AAA
Data = 21°C
Message 1
Address BBB
Data = 21°C
Message 2
Address CCC

14. • Public Mode
• Private Mode
• Restricter Mode
Channel Mode

15. Public Mode
address = root
address

16. Public Mode
next_root
root = AAA
next_root = BBB
Payload = 20°C
Address = AAA
address = next_root
root = BBB
next_root = CCC
Payload = 21°C
Address = CCC
address = next_root

17. Private Mode
address = hash(root)
root

18. root
Private Mode
root = AAA
next_root = BBB
Payload = 20°C
Address = QWE
address = hash(next_root)
QWE = hash(BBB)
root = BBB
next_root = CCC
Payload = 21°C
Address = ASD
address = hash(next_root)
ASD = hash(CCC)

19. Restricter Mode
address = hash(root)
side_key

20. root = AAA
next_root = BBB
Payload = %IOP
Address = QWE
address = hash(next_root)
QWE = hash(BBB)
sidekey =
fishfish
payload
decrypted =
20°C
root = BBB
next_root = CCC
Payload = %JKL
Address = ASD
address = hash(next_root)
ASD = hash(CCC)
sidekey =
fishfish
payload
decrypted =
21°C
root side_key
Restricter Mode

22. 20°C
21°C
21°C
20°C 21°C 21°C
MAM

24. Demo
https://bit.ly/2yrO8RV

25. Private ModePublic Mode Restricter Mode
"state": {
"subscribed": [],
"channel": {
"side_key": null,
"mode": "public",
"next_root": "CJ...SD",
"security": "2",
"start": 1,
"count": 1,
"next_count": 1,
"index": 0
},
"seed": "OJ...LL"
},
"payload": "AH...A9",
"root": "KERFP...AQFUI",
"address": "KERFP...AQFUI"
"state": {
"subscribed": [],
"channel": {
"side_key": null,
"mode": "private",
"next_root": "MP...CR",
"security": "2",
"start": 1,
"count": 1,
"next_count": 1,
"index": 0
},
"seed": "ZS...KN"
},
"payload": "AH...Z9",
"root": "HXMCV...XOBLU",
"address": "UDJSG...HKYEQ"
""state": {
"subscribed": [],
"channel": {
"side_key": “UC…WC”,
"mode": "restricted",
"next_root": "FZ...ZB",
"security": "2",
"start": 1,
"count": 1,
"next_count": 1,
"index": 0
},
"seed": "KO...FM"
},
"payload": "AH...99",
"root": "ATYBW...LGVMX",
"address": "JANOP...SFWEL"

26. MAM object

27. "state": {
"subscribed": [],
"channel": {
“side_key": String
“mode”: String
"next_root": String
“security": Int
"start": Int
"count": Int,
"next_count": Int,
"index": Int
},
"seed": String
},
"payload": String
“root”: String
"address": String
side_key
Restricted Mode
side_key

28. "state": {
"subscribed": [],
"channel": {
“side_key": String
“mode”: String
"next_root": String
“security": Int
"start": Int
"count": Int,
"next_count": Int,
"index": Int
},
"seed": String
},
"payload": String
“root”: String
"address": String
mode
Public Mode
address
Private Mode
root
root address
Restricted Mode
root
side_key

29. "state": {
"subscribed": [],
"channel": {
“side_key": String
“mode”: String
"next_root": String
“security": Int
"start": Int
"count": Int,
"next_count": Int,
"index": Int
},
"seed": String
},
"payload": String
“root”: String
"address": String
next_root
next_root Message chain
next_root
MerkleTree

30. root
A”=Hash(A’)
Hash(A”B”)
A’
A B
B’
B”=Hash(B’) C”=Hash(C’)
C’
C D
D’
D”=Hash(D’)
Hash(C”D”)
next_root
priavte_Key=
fun(seed,key index,sec.level)
address=hash*(Private_key)

31. "state": {
"subscribed": [],
"channel": {
“side_key": String
“mode”: String
"next_root": String
“security": Int
"start": Int
"count": Int,
"next_count": Int,
"index": Int
},
"seed": String
},
"payload": String
“root”: String
"address": String
security
1 , 2 , 3

32. "state": {
"subscribed": [],
"channel": {
“side_key": String
“mode”: String
"next_root": String
“security": Int
"start": Int
"count": Int,
"next_count": Int,
"index": Int
},
"seed": String
},
"payload": String
“root”: String
"address": String
start
Message chain
MerkleTree Seed

33. start
0’
0
root
private_key
address
1”=Hash(1’)
1’
1 2
2’
2”=Hash(2’)
root
start 0 1

34. "state": {
"subscribed": [],
"channel": {
"side_key": null,
"mode": "public",
"next_root": “HM..LU”,
"security": "2",
"start": 1,
"count": 1,
"next_count": 1,
"index": 0
},
"seed": "OJ...LL"
},
"payload": "AH...A9",
"root": "KERFP...AQFUI",
"address": "KERFP...AQFUI"
"state": {
"subscribed": [],
"channel": {
"side_key": null,
"mode": "public",
"next_root": “AT..MX”,
"security": "2",
"start": 2,
"count": 1,
"next_count": 1,
"index": 0
},
"seed": "OJ...LL"
},
"payload": "AH...Z9",
"root": "HXMCV...XOBLU",
"address": “HXMCV...XOBLU"
""state": {
"subscribed": [],
"channel": {
"side_key": null,
"mode": "public",
"next_root": "FZ...ZB",
"security": "2",
"start": 3,
"count": 1,
"next_count": 1,
"index": 0
},
"seed": "OJ...LL"
},
"payload": "AH...99",
"root": "ATYBW...LGVMX",
"address": "ATYBW...LGVMX"

35. "state": {
"subscribed": [],
"channel": {
“side_key": String
“mode”: String
"next_root": String
“security": Int
"start": Int
"count": Int,
"next_count": Int,
"index": Int
},
"seed": String
},
"payload": String
“root”: String
"address": String
count
MerkleTree

36. count
0’
0
root 1”=Hash(1’)
1’
1 2
2’
2”=Hash(2’)
root
count 1 2
private_key
address

37. "state": {
"subscribed": [],
"channel": {
“side_key": String
“mode”: String
"next_root": String
“security": Int
"start": Int
"count": Int,
"next_count": Int,
"index": Int
},
"seed": String
},
"payload": String
“root”: String
"address": String
next_count
next_root
MerkleTree
next_count MerkleTree

39. 0’
0
root
1’
1 2
2’
root
root
3’
3 4
4’ 5’
5 6
6’
priavte_Key
address
start
count
next_count
next_root
0 1 3
1 2 4
2 4
BBB CCC
AAA
BBB
CCC

40. "state": {
"subscribed": [],
"channel": {
“side_key": String
“mode”: String
"next_root": String
“security": Int
"start": Int
"count": Int,
"next_count": Int,
"index": Int
},
"seed": String
},
"payload": String
“root”: String
"address": String
index
index key index

41. index
root
index 0 1 2 3

42. "state": {
"subscribed": [],
"channel": {
“side_key": String
“mode”: String
"next_root": String
“security": Int
"start": Int
"count": Int,
"next_count": Int,
"index": Int
},
"seed": String
},
"payload": String
“root”: String
"address": String
seed
Seed Message chain
Message chain Seed

43. "state": {
"subscribed": [],
"channel": {
“side_key": String
“mode”: String
"next_root": String
“security": Int
"start": Int
"count": Int,
"next_count": Int,
"index": Int
},
"seed": String
},
"payload": String
“root”: String
"address": String
payload
message nonce signature number of sibilings siblings

44. "state": {
"subscribed": [],
"channel": {
“side_key": String
“mode”: String
"next_root": String
“security": Int
"start": Int
"count": Int,
"next_count": Int,
"index": Int
},
"seed": String
},
"payload": String
“root”: String
"address": String
root
Merkle Root

45. root
root

46. "state": {
"subscribed": [],
"channel": {
“side_key": String
“mode”: String
"next_root": String
“security": Int
"start": Int
"count": Int,
"next_count": Int,
"index": Int
},
"seed": String
},
"payload": String
“root”: String
"address": String
address
attchedToTangle

47. MAM Bundle

48. MAM Bundle
Transaction[0] Transaction[1] Transaction[2]
Signature Section MAM Section
address=KERFP.. address=KERFP.. address=KERFP..
MerkleTree (1/2) MerkleTree (2/2) Message
*Signature = sec.lvl * 2187[trytes]
*MAM Section 2187[trytes]
i.e.:sec.lvl=2

49. MAM Section
MAM Section
nextRoot Branch Index Siblings Completed

50. MAM Section - nextRoot
merkle tree

51. MAM Section - Branch Index
root
index 0 1 2 3
Branch Index

52. MAM Section - Siblings
Branch Index
= 0
root
A”=Hash(A’)
Hash(A”B”)
A’
A B
B’
B”=Hash(B’) C”=Hash(C’)
C’
C D
D’
D”=Hash(D’)
Hash(C”D”)
Sibilings of A’
Branch Index
Sibings

53. MAM Section - Completed
MessageTrytes
Branch
Index
0
Siblings of Branch Index = 0
B” =Hash(B’) Hash(C”D”)
nextRoot
HM..LU
Message
20°C
message
nextRoot branch_index Siblings
messageTrytes
root sideKey
Side_key
Transaction[2]
MAM Section
address=KERFP..
Message

54. Signature Section
MAM Section
Bundle Signature
Signature
Transaction Signature Section

55. Signature Section - Signing
Private Key = key seed branch_index security
Priavate Key
Signed Data
MessageTrytes
Signature
length = sec.lvl * 2187[trytes]

56. MAM Fetch

57. MAM Fetch
MAM
root
Bundle
side_key MAM Secion
messageTrytes : nextRoot ,Branch Index ,Sibilings
branch_index address
branch_index address siblings
temp_root
if temp_root = root

58. • Snapshot
• Tangle Transaction confirmed
•

59. • ABmushi - IOTA: MAM Eloquently Explained : https://medium.com/@abmushi/iota-mam-eloquently-explained-d7505863b413
• Paul Handy - Introducing Masked Authenticated Messaging : https://blog.iota.org/introducing-masked-authenticated-messaging-e55c1822d50e
• mobilefish.com - IOTA tutorial [19-21]: Masked Authenticated Messaging : https://www.youtube.com/channel/UCG5_CT_KjexxjbgNE4lVGkg/
videos
• iotaledger - MAM/mam.rs : https://github.com/iotaledger/MAM/blob/master/mam/src/mam.rs
• iotaledger - mam.client.js : https://github.com/iotaledger/mam.client.js
• - IOTA: MAM Eloquently Explained ( ) : https://hackmd.io/s/HyxIu0asf#MAM-Publish-102-MAM-Section-—-nextRoot
• HexRabbit - Iota MAM : https://hackmd.io/s/rJkpIrrbM
reference

61. MerkleTree
MerkleTree HashTree
hash
Merkle hash
hash

62. MerkleTree