OCB3
OCB3 (Offset CodeBook Mode version 3) is a highly efficient authenticated encryption mode that provides both confidentiality and authenticity in a single pass. It supports parallel processing and was standardized in RFC 7253. OCB3 improves upon earlier OCB versions with enhanced security and performance.
Properties
| Property |
Value |
| Category |
Cipher Modes |
| Sub-category |
Authenticated Encryption |
| Security status |
🛡️ Secure |
| Complexity |
Research |
| Inventor |
Phillip Rogaway, Ted Krovetz |
| Year |
2011 |
| Origin |
🇺🇸 United States |
| Source |
algorithms/modes/ocb.js |
Parameters
| Parameter |
Supported values |
| IV sizes |
1 byte (8 bits) to 15 bytes (120 bits) |
Capabilities
| Flag |
Value |
RequiresIV |
Yes |
Security
Status: 🛡️ Secure
Known vulnerabilities
| Issue |
Description |
Mitigation |
| Nonce Reuse |
Reusing nonces with the same key completely breaks OCB3 security. Each encryption must use a unique nonce. |
— |
| Patent History |
OCB was patent-encumbered until 2028. Now free for use but still requires careful implementation. |
— |
Documentation
References
Test vectors
6 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — RFC 7253 AES-128 OCB TAGLEN128, N=…01, 8-byte plaintext
| Field |
Value |
cipher |
AES |
key |
000102030405060708090a0b0c0d0e0f |
nonce |
bbaa99887766554433221101 |
aad |
0001020304050607 |
tagLength |
16 |
input |
0001020304050607 |
expected |
6820b3657b6f615a5725bda0d3b4eb3a257c9af1f8f03009 |
Vector 2 — RFC 7253 AES-128 OCB TAGLEN128, N=…03, empty AAD
| Field |
Value |
cipher |
AES |
key |
000102030405060708090a0b0c0d0e0f |
nonce |
bbaa99887766554433221103 |
aad |
(empty) |
tagLength |
16 |
input |
0001020304050607 |
expected |
45dd69f8f5aae72414054cd1f35d82760b2cd00d2f99bfa9 |
Vector 3 — RFC 7253 AES-128 OCB TAGLEN128, N=…04, one full block
| Field |
Value |
cipher |
AES |
key |
000102030405060708090a0b0c0d0e0f |
nonce |
bbaa99887766554433221104 |
aad |
000102030405060708090a0b0c0d0e0f |
tagLength |
16 |
input |
000102030405060708090a0b0c0d0e0f |
expected |
571d535b60b277188be5147170a9a22c3ad7a4ff3835b8c5701c1ccec8fc3358 |
Vector 4 — RFC 7253 AES-128 OCB TAGLEN128, N=…07, block plus half block
| Field |
Value |
cipher |
AES |
key |
000102030405060708090a0b0c0d0e0f |
nonce |
bbaa99887766554433221107 |
aad |
000102030405060708090a0b0c0d0e0f1011121314151617 |
tagLength |
16 |
input |
000102030405060708090a0b0c0d0e0f1011121314151617 |
expected |
1ca2207308c87c010756104d8840ce19 52f09673a448a122c92c62241051f573 56d7f3c90bb0e07f |
Vector 5 — RFC 7253 AES-128 OCB TAGLEN128, N=…0D, 40-byte plaintext
| Field |
Value |
cipher |
AES |
key |
000102030405060708090a0b0c0d0e0f |
nonce |
bbaa9988776655443322110d |
aad |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 2021222324252627 |
tagLength |
16 |
input |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 2021222324252627 |
expected |
d5ca91748410c1751ff8a2f618255b68 a0a12e093ff454606e59f9c1d0ddc54b 65e8628e568bad7aed07ba06a4a69483 a7035490c5769e60 |
Vector 6 — RFC 7253 OCB TAGLEN96 with key 0F0E…0100
| Field |
Value |
cipher |
AES |
key |
0f0e0d0c0b0a09080706050403020100 |
nonce |
bbaa9988776655443322110d |
aad |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 2021222324252627 |
tagLength |
12 |
input |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 2021222324252627 |
expected |
1792a4e31e0755fb03e31b22116e6c2d df9efd6e33d536f1a0124b0a55bae884 ed93481529c76b6ad0c515f4d1cdd4fd ac4f02aa |
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