Hawkynt

VMAC

Very high-speed message authentication code using universal hashing and AES-based key derivation. Designed for high performance with formal security proofs.

Properties

Property	Value
Category	Message Authentication
Sub-category	Universal Hashing MAC
Security status	Not classified
Complexity	Advanced
Inventor	Ted Krovetz, Wei Dai
Year	2007
Origin	🇺🇸 United States
Source	algorithms/mac/vmac.js

Parameters

Parameter	Supported values
MAC sizes	8 bytes (64 bits) to 16 bytes (128 bits) in steps of 8 bytes

Capabilities

Flag	Value
NeedsKey	Yes

Security

Status: not classified — treat as unverified.

Known vulnerabilities

Issue	Description	Mitigation
Nonce Reuse	Using the same nonce with the same key completely breaks security	—
Side-Channel Attacks	Implementation must use constant-time operations to prevent timing attacks	—

Documentation

• VMAC Draft Specification
• Fastcrypto VMAC Page
• Message Authentication on 64-bit Architectures (Krovetz, FSE 2006)

References

• Crypto++ VMAC Implementation
• Ted Krovetz’s Reference Code
• VMAC Test Vectors

Test vectors

16 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.

Vector 1 — VMAC(AES)-64: Empty message

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	8
input	(empty)
expected	2576be1c56d8b81b

Vector 2 — VMAC(AES)-64: ‘abc’

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	8
input	616263
expected	2d376cf5b1813ce5

Vector 3 — VMAC(AES)-64: 16 x ‘abc’

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	8
input	61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263
expected	e8421f61d573d298

Vector 4 — VMAC(AES)-128: Empty message

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	16
input	(empty)
expected	472766c70f74ed23481d6d7de4e80dac

Vector 5 — VMAC(AES)-128: ‘abc’

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	16
input	616263
expected	4ee815a06a1d71edd36fc75d51188a42

Vector 6 — VMAC(AES)-128: 16 x ‘abc’

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	16
input	61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263
expected	09f2c80c8e1007a0c12fae19fe4504ae

Vector 7 — VMAC(AES)-64: 42 x ‘abc’ + ‘ab’ (128 bytes, exactly one L1 segment)

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	8
input	61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 62636162636162636162636162636162
expected	d638b73921f184de

Vector 8 — VMAC(AES)-128: 42 x ‘abc’ + ‘ab’ (128 bytes, exactly one L1 segment)

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	16
input	61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 62636162636162636162636162636162
expected	f7e95fe3da8db9e6bb973e65d0b4cea5

Vector 9 — VMAC(AES)-64: 129 x ‘a’ (one byte past the L1 segment)

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	8
input	61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61
expected	86348387d13d8233

Vector 10 — VMAC(AES)-128: 129 x ‘a’ (one byte past the L1 segment)

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	16
input	61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61
expected	a7e52c3289d9b73b53576f059585ee79

Vector 11 — VMAC(AES)-64: 65 x ‘abc’ (195 bytes, two L1 segments)

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	8
input	61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 616263
expected	e86a86ec77a8bf61

Vector 12 — VMAC(AES)-128: 65 x ‘abc’ (195 bytes, two L1 segments)

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	16
input	61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 616263
expected	0a1b2f973044f469f405917e45010334

Vector 13 — VMAC(AES)-64: 100 x ‘abc’ (300 bytes, three L1 segments)

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	8
input	61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 … (300 bytes; the full value is in the source)
expected	4492df6c5cac1bbe

Vector 14 — VMAC(AES)-128: 100 x ‘abc’ (300 bytes, three L1 segments)

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	16
input	61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 … (300 bytes; the full value is in the source)
expected	66438817154850c61d8a412164803bcb

Vector 15 — VMAC(AES)-64: 170 x ‘abc’ + ‘ab’ (512 bytes, exactly four L1 segments)

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	8
input	61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 … (512 bytes; the full value is in the source)
expected	9da310281e6fd0a0

Vector 16 — VMAC(AES)-128: 170 x ‘abc’ + ‘ab’ (512 bytes, exactly four L1 segments)

Field	Value
key	6162636465666768696a6b6c6d6e6f70
nonce	6263646566676869
outputSize	16
input	61626361626361626361626361626361 62636162636162636162636162636162 63616263616263616263616263616263 61626361626361626361626361626361 … (512 bytes; the full value is in the source)
expected	bf53b8d2d70c05a85880c2e21caf1299

---

← All algorithms

This site is open source. Improve this page.