# TLS_ECCPWD_WITH_AES_256_CCM_SHA384 cipher suite

> TLS_ECCPWD_WITH_AES_256_CCM_SHA384 (0xC0,0xB3): ECCPWD/ECCPWD · AES-256-CCM · TLS 1.2, TLS 1.3. ssl.sh rating: Secure. OpenSSL/GnuTLS names and Nginx/Apache config.

Source: https://ssl.sh/ciphers/tls-eccpwd-with-aes-256-ccm-sha384/
Last updated: 2026-11-10

TLS_ECCPWD_WITH_AES_256_CCM_SHA384 (0xC0,0xB3) is a cipher suite for TLS 1.2, TLS 1.3: ECCPWD key exchange, ECCPWD authentication, AES-256-CCM encryption and AEAD message authentication. ssl.sh rates it Secure.

| Field | Value |
|---|---|
| IANA | TLS_ECCPWD_WITH_AES_256_CCM_SHA384 |
| Hex code | 0xC0,0xB3 |
| OpenSSL | Not available in OpenSSL 3.5 |
| GnuTLS | - |
| Key exchange | ECCPWD |
| Authentication | ECCPWD |
| Encryption | AES-256-CCM |
| MAC | AEAD |
| TLS versions | TLS 1.2, TLS 1.3 |
| Rating | Secure |
| IANA "Recommended" | N |
| References | RFC 8492 |

## What each component means

A [cipher suite](https://ssl.sh/glossary/cipher-suite/) names the algorithms a client and server agree on in one handshake. TLS_ECCPWD_WITH_AES_256_CCM_SHA384 combines ECCPWD key exchange, ECCPWD authentication, AES-256-CCM encryption and AEAD integrity protection. Each part is explained below with its known weaknesses; for the bigger picture see [how cipher suites work](https://ssl.sh/learn/cipher-suites/).

Key exchange and authentication: ECCPWD, the password-based TLS-PWD exchange of [RFC 8492](https://www.rfc-editor.org/rfc/rfc8492) (2019), an Informational RFC. Both sides prove knowledge of a shared password through an elliptic-curve exchange designed to resist offline dictionary attacks, with no certificates involved. Its four suites (AES-GCM and AES-CCM with SHA-256 or SHA-384) are registered for both TLS 1.2 and TLS 1.3.

Encryption: AES with a 256-bit key, the 128-bit block cipher of FIPS 197 (2001). Most server and phone CPUs have AES instructions (AES-NI on x86, the ARMv8 cryptography extensions), which make it fast and avoid the cache-timing leaks of table-based software implementations.

Mode: CCM (counter mode with CBC-MAC), an [AEAD](https://ssl.sh/glossary/aead/) with a 16-byte authentication tag. It only uses the block cipher's encryption function, so it suits small devices that have a hardware block cipher but no GCM support.

Integrity: there is no separate MAC because the AEAD tag authenticates every record. The SHA384 at the end of the name selects the TLS 1.2 PRF hash used to derive keys and compute the Finished messages.

## Why this rating

- Ephemeral key exchange (forward secrecy) plus an AEAD cipher, the combination TLS 1.2 best practice asks for.

## Which TLS libraries support it

Support for TLS_ECCPWD_WITH_AES_256_CCM_SHA384 as read from each library's own source code or official documentation on 2026-11-10. “Enabled by default” means the library negotiates it with no configuration; “off by default” means it is implemented but has to be switched on.

| Library | Status | Details |
|---|---|---|
| OpenSSL 3.5 | Not supported | - |
| GnuTLS | Not supported | - |
| BoringSSL | Not supported | - |
| Go crypto/tls | Not supported | - |
| NSS 3.133 | Not supported | - |
| Firefox | Not supported | - |
| Java 21 (SunJSSE) | Not supported | - |
| Windows Schannel (Windows 11 / Server 2022) | Not supported | - |
| rustls 0.23.46 | Not supported | - |

None of the 9 libraries tracked here enables it by default. None of them implements it.

NSS shows the library's own defaults; Firefox switches every NSS suite off at start-up and re-enables only those with a security.ssl3.* or security.tls13.* preference. Java defaults are derived from the jdk.tls.disabledAlgorithms value Oracle documents for JDK 21, which later updates may extend. The OpenSSL and GnuTLS rows only show whether the suite is implemented.

- [BoringSSL — ssl/ssl_cipher.cc (main)](https://boringssl.googlesource.com/boringssl/+/refs/heads/main/ssl/ssl_cipher.cc) (2026-11-10)
- [Go — src/crypto/tls/cipher_suites.go (master)](https://github.com/golang/go/blob/master/src/crypto/tls/cipher_suites.go) (2026-11-10)
- [Go — src/crypto/tls/defaults.go (master)](https://github.com/golang/go/blob/master/src/crypto/tls/defaults.go) (2026-11-10)
- [NSS — lib/ssl/ssl3con.c (as vendored in Firefox)](https://github.com/mozilla-firefox/firefox/blob/main/security/nss/lib/ssl/ssl3con.c) (2026-11-10)
- [NSS — TAG-INFO](https://github.com/mozilla-firefox/firefox/blob/main/security/nss/TAG-INFO) (2026-11-10)
- [Firefox — security/manager/ssl/nsNSSComponent.cpp](https://github.com/mozilla-firefox/firefox/blob/main/security/manager/ssl/nsNSSComponent.cpp) (2026-11-10)
- [Firefox — modules/libpref/init/StaticPrefList.yaml](https://github.com/mozilla-firefox/firefox/blob/main/modules/libpref/init/StaticPrefList.yaml) (2026-11-10)
- [Oracle — JDK 21 Providers Documentation: SunJSSE Cipher Suites](https://docs.oracle.com/en/java/javase/21/security/oracle-providers.html#GUID-7093246A-31A3-4304-AC5F-5FB6400405E2) (2026-11-10)
- [Oracle — JDK 21 JSSE Reference Guide: jdk.tls.disabledAlgorithms](https://docs.oracle.com/en/java/javase/21/security/java-secure-socket-extension-jsse-reference-guide.html) (2026-11-10)
- [Microsoft Learn — TLS Cipher Suites in Windows 11](https://learn.microsoft.com/en-us/windows/win32/secauthn/tls-cipher-suites-in-windows-11) (2026-11-10)
- [Microsoft Learn — TLS Cipher Suites in Windows Server 2022](https://learn.microsoft.com/en-us/windows/win32/secauthn/tls-cipher-suites-in-windows-server-2022) (2026-11-10)
- [docs.rs — rustls 0.23.46 crypto::aws_lc_rs (default provider)](https://docs.rs/rustls/0.23.46/src/rustls/crypto/aws_lc_rs/mod.rs.html) (2026-11-10)

## History and standards status

TLS_ECCPWD_WITH_AES_256_CCM_SHA384 (0xC0,0xB3) is registered in the IANA TLS Cipher Suites registry with [RFC 8492](https://www.rfc-editor.org/rfc/rfc8492), “Secure Password Ciphersuites for Transport Layer Security (TLS)” (February 2019, Informational) as its specification. The registry marks it N, which per [RFC 8447](https://www.rfc-editor.org/rfc/rfc8447) (2018) means it either hasn't been through the IETF consensus process, has limited applicability or is meant only for specific use cases, not necessarily that it is flawed.

## How to test whether a server accepts it

OpenSSL 3.5 cannot offer TLS_ECCPWD_WITH_AES_256_CCM_SHA384, so openssl s_client can't test it directly; use a scanner that implements the suite itself.

nmap's ssl-enum-ciphers script connects repeatedly, trying one suite at a time, and lists every suite the server accepts with a grade from A to F. Look for TLS_ECCPWD_WITH_AES_256_CCM_SHA384 in its output:

```bash
nmap --script ssl-enum-ciphers -p 443 example.com
```

To decode a name or hex code, use the [cipher suite lookup](https://ssl.sh/tools/cipher-suite-lookup/); the [SSL checker](https://ssl.sh/tools/ssl-checker/) shows which protocol versions a live server accepts and the cipher suite it negotiates.

## FAQ

### Is TLS_ECCPWD_WITH_AES_256_CCM_SHA384 secure?

Cryptographically, yes: ssl.sh rates it secure. Ephemeral key exchange (forward secrecy) plus an AEAD cipher, the combination TLS 1.2 best practice asks for.

### Can TLS_ECCPWD_WITH_AES_256_CCM_SHA384 be used with TLS 1.3?

Yes. Its registry entry covers both TLS 1.2 and TLS 1.3 ([RFC 8492](https://www.rfc-editor.org/rfc/rfc8492)).

### How do I disable TLS_ECCPWD_WITH_AES_256_CCM_SHA384 in Nginx or Apache?

There is nothing to disable: OpenSSL 3.5, which Nginx and Apache httpd normally use, does not implement TLS_ECCPWD_WITH_AES_256_CCM_SHA384, so they cannot negotiate it.

### Which clients and libraries still support TLS_ECCPWD_WITH_AES_256_CCM_SHA384?

Not supported: OpenSSL 3.5, GnuTLS, BoringSSL, Go crypto/tls, NSS 3.133, Firefox, Java 21 (SunJSSE), Windows Schannel (Windows 11 / Server 2022) and rustls 0.23.46.