TVM on Tetra

Tycho and TON TVM Compatibility

TON and Tycho are fully compatible at the TVM level, meaning they share the same execution model. Tycho, however, uses its own Rust-based TVM implementation.

The differences only appear in specific opcodes and related rules. Understanding them is useful for developers working across multiple networks.

Key Differences

1. Replay Attack Protection

Tycho provides built-in protection against replay attacks between networks.

• No extra action is required from developers.

• Certain opcodes, such as CHKSIGNU and CHKSIGNS, are affected, so it’s helpful to understand how this mechanism works.

2. BLS Cryptography

• BLS cryptography is not implemented in Tycho TVM.

Opcode

Opcode	Tycho	TON
SIGNDOMAIN	✅
SIGNDOMAIN_POP	✅
SIGNDOMAIN_PUSH	✅
BLS_VERIFY		✅
BLS_AGGREGATE		✅
BLS_FASTAGGREGATEVERIFY		✅
BLS_AGGREGATEVERIFY		✅
BLS_G1_ADD		✅
BLS_G1_SUB		✅
BLS_G1_NEG		✅
BLS_G1_MUL		✅
BLS_G1_MULTIEXP		✅
BLS_G1_ZERO		✅
BLS_MAP_TO_G1		✅
BLS_G1_INGROUP		✅
BLS_G1_ISZERO		✅
BLS_G2_ADD		✅
BLS_G2_SUB		✅
BLS_G2_NEG		✅
BLS_G2_MUL		✅
BLS_G2_MULTIEXP		✅
BLS_G2_ZERO		✅
BLS_MAP_TO_G2		✅
BLS_G2_INGROUP		✅
BLS_G2_ISZERO		✅
BLS_PAIRING		✅
BLS_PUSHR		✅
CHKSIGNU	✅	✅
CHKSIGNS	✅	✅
Others	✅	✅

SIGNDOMAIN Opcodes

Tycho introduces SIGNDOMAIN* opcodes to manage the signature domain stack:

Opcode	Behavior
SIGNDOMAIN	Pushes the current signature domain onto the stack.
SIGNDOMAIN_POP	Pushes the current domain and then removes it from the stack.
SIGNDOMAIN_PUSH	Adds a new signature domain to the stack and sets it as current.