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Mehr Protocol Specification v1.0

This page is the normative reference for the Mehr protocol. Individual documentation pages provide detailed explanations; this page summarizes the protocol constants, wire formats, and layer dependencies in one place.

Status

Version	1.0
Status	Design complete, pre-implementation
Normative sections	Layers 0–5 (transport through services)
Informative sections	Layer 6 (applications), hardware reference, roadmap

Protocol Constants

Constant	Value	Defined In
Gossip interval	60 seconds	Network Protocol
Protocol overhead budget	≤10% of link bandwidth	Bandwidth Budget
CompactPathCost size	6 bytes (constant)	Network Protocol
MehrExtension magic byte	0x4E ('N')	Network Protocol
Destination hash size	16 bytes (128-bit)	Network Protocol
Smallest MHR unit	1 μMHR	MHR Token
Supply ceiling	2^64 μMHR (asymptotic)	MHR Token
Default relay lottery probability	1/100	Stochastic Rewards
Payment channel state size	200 bytes	Payment Channels
Dispute challenge window	2,880 gossip rounds (~48h)	Payment Channels
Channel abandonment threshold	4 epochs	Payment Channels
Epoch trigger: settlement count	≥10,000 batches	CRDT Ledger
Epoch trigger: GSet memory	≥500 KB	CRDT Ledger
Epoch acknowledgment threshold	67% of active set	CRDT Ledger
Epoch verification window	4 epochs after activation	CRDT Ledger
Bloom filter FPR (epoch)	0.01%	CRDT Ledger
DHT replication factor	k=3	MHR-DHT
DHT XOR weight (w_xor)	0.7	MHR-DHT
Storage chunk size	4 KB	MHR-Store
Presence beacon size	20 bytes	Discovery
Presence beacon interval	10 seconds	Discovery
Transitive credit limit	10% per hop, max 2 hops	Trust & Neighborhoods
Max scopes per node	8	Trust & Neighborhoods
Max scope depth	8 segments	Trust & Neighborhoods
Max scope segment length	32 characters	Trust & Neighborhoods
Vouch expiry (default)	30 epochs	Identity & Claims
Kickback rate range	0–255 (u8)	MHR-Store
Default kickback rate	128 (~50%)	Content Propagation
IdentityClaim min size	~100 bytes	Identity & Claims
Vouch size	113 bytes	Identity & Claims
Geo verification: min vouches	3 (for Verified level)	Voting

Cryptographic Primitives

Purpose	Algorithm	Output / Key Size
Identity / Signing	Ed25519	256-bit (32-byte public key)
Key Exchange	X25519 (Curve25519 DH)	256-bit
Identity Hashing	Blake2b	256-bit → 128-bit truncated
Content Hashing	Blake3	256-bit
Symmetric Encryption	ChaCha20-Poly1305	256-bit key, 96-bit nonce
Relay Lottery (VRF)	ECVRF-ED25519-SHA512-TAI (RFC 9381)	80-byte proof
Erasure Coding	Reed-Solomon	Configurable k,m

Layer Dependency Graph

Layer 6: Applications
  ├── Messaging, Social, Identity, Voice, Naming, Voting, Forums, Hosting
  └── depends on ↓

Layer 5: Service Primitives
  ├── MHR-Store, MHR-DHT, MHR-Pub, MHR-Compute
  └── depends on ↓

Layer 4: Capability Marketplace
  ├── Discovery, Agreements, Verification
  └── depends on ↓

Layer 3: Economic Protocol
  ├── MHR Token, Stochastic Rewards, CRDT Ledger, Trust Neighborhoods, Propagation
  └── depends on ↓

Layer 2: Security
  ├── Link encryption, E2E encryption, Authentication, Key management
  └── depends on ↓

Layer 1: Network Protocol
  ├── Identity, Addressing, Routing, Gossip, Congestion Control
  └── depends on ↓

Layer 0: Physical Transport
  └── LoRa, WiFi, Cellular, Ethernet, BLE, Fiber, Serial

Each layer depends only on the layer directly below it. Applications never touch transport details. Payment never touches routing internals.

Serialization Rules

All Mehr wire formats use the following conventions:

Rule	Value
Byte order	Little-endian for all multi-byte integers (u16, u32, u64, i64)
Encoding	Fixed-size binary fields; no self-describing framing (not CBOR, not JSON)
TLV extensions	Type (u8), Length (u8, max 255), Data (variable). Used in MehrExtension only
Strings	UTF-8, length-prefixed with u16 (community labels, function IDs)
Hashes	Raw bytes, no hex encoding on the wire
Signatures	Raw 64-byte Ed25519 signatures, no ASN.1/DER wrapping
Normalized scores	Computed on decoded values, then divided by the max decoded value in the candidate set. Result is IEEE 754 f32 on nodes that support FP; 16-bit fixed-point (Q0.16, value × 65535) on constrained nodes. Both yield equivalent routing decisions within rounding tolerance

Wire Format Summary

Packet Format (Reticulum-derived)

[HEADER 2B] [DEST_HASH 16B] [CONTEXT 1B] [DATA 0-465B]
Max packet size: 484 bytes
Source address: NOT PRESENT (structural sender anonymity)

Mehr Announce Extension

[MAGIC 1B: 0x4E] [VERSION 1B] [CompactPathCost 6B] [TLV extensions...]
Minimum: 8 bytes. Carried in announce DATA field.

CompactPathCost

[cumulative_cost 2B] [worst_latency_ms 2B] [bottleneck_bps 1B] [hop_count 1B]
Total: 6 bytes (constant regardless of path length)

Payment Channel State

[channel_id 16B] [party_a 16B] [party_b 16B] [balance_a 8B]
[balance_b 8B] [sequence 8B] [sig_a 64B] [sig_b 64B]
Total: 200 bytes

Specification Sections

Spec Section	Documentation Page
0. Design Philosophy	Introduction
1. Layer 0: Physical Transport	Physical Transport
2. Layer 1: Network Protocol	Network Protocol
3. Layer 2: Security	Security
4. Layer 3: Economic Protocol	MHR Token, Stochastic Relay Rewards, CRDT Ledger, Trust & Neighborhoods, Real-World Economics
5. Layer 4: Capability Marketplace	Overview, Discovery, Agreements, Verification
6. Layer 5: Service Primitives	MHR-Store, MHR-DHT, MHR-Pub, MHR-Compute
7. Layer 6: Applications	Messaging, Social, Voice, Naming, Community Apps, Hosting
8. Hardware Reference	Reference Designs, Device Tiers
9. Implementation Roadmap	Roadmap
10. Design Decisions	Design Decisions
11. Open Questions	Open Questions

Version History

Version	Status	Description
v0.1-v0.5	Superseded	Early design iterations
v0.8	Superseded	Introduced explicit community zones (later replaced by trust neighborhoods)
v1.0	Current	Consolidated specification — Reticulum foundation, stochastic relay rewards, emergent trust neighborhoods

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This specification consolidates design work from v0.1 through v1.0. The foundation — Reticulum-based transport, cryptographic identity, Kleinberg small-world routing, stochastic relay rewards, CRDT settlement, epoch compaction, emergent trust neighborhoods, and the capability marketplace — is the protocol. Everything above it — storage, compute, pub/sub, naming, and applications — are services built on that foundation.