# What does ECDHE Ecdsa AES128 GCM SHA256 mean?

## What does ECDHE Ecdsa AES128 GCM SHA256 mean?

The ECDSA in ECDHE-ECDSA-AES128-GCM-SHA256 means you need the Elliptic Curve Digital Signature Algorithm to authenticate that key. Because you don’t have those kind of keys, the command fails. However, ECDHE-RSA-AES256-GCM-SHA384 works because it uses RSA keys which you have.

**What is DHE cipher?**

The Diffie–Hellman key exchange method allows two parties that have no prior knowledge of each other to jointly establish a shared secret key over an insecure channel. This key can then be used to encrypt subsequent communications using a symmetric-key cipher.

**Is AES256 GCM SHA384 secure?**

Non-secure cipher suites: ECDHE-RSA-AES256-SHA. ECDHE-RSA-AES128-SHA. AES256-GCM-SHA384.

### Is RSA a cipher suite?

Cipher suites are named combinations of: Key Exchange Algorithms (RSA, DH, ECDH, DHE, ECDHE, PSK)

**What is ECDHE RSA?**

ECDHE means that the client and server will agree on encryption keys using Ephemeral Elliptic Curve Diffie-Hellman. RSA means that the client will verify that the key is valid using the RSA algorithm to communications.

**What is ECDSA encryption?**

Elliptic Curve Digital Signature Algorithm, or ECDSA, is one of the more complex public key cryptography encryption algorithms. Keys are generated via elliptic curve cryptography that are smaller than the average keys generated by digital signing algorithms.

#### What is aes128 encryption?

128-bit AES encryption refers to the process of concealing plaintext data using an AES key length of 128 bits. 128-bit AES encryption uses 10 transformation rounds to convert plaintext into ciphertext and is approved by the National Security Agency (NSA) to protect secret but not top-secret government information.

**Is aes128 SHA1 secure?**

However SHA1 is still secure, provided you use a relatively short key lifetime and, more importantly, always pair it with a strong encryption algorithm (such as AES-128, AES-192 or AES-256).

**What is dhe RSA?**

Within DHE-RSA, the server signs the Diffie-Hellman parameter (using a private key from an RSA key pair) to create a pre-master secret, and where a master is created which is then used to generate a shared symmetric encryption key.

## What is RSA or ECDSA?

ECDSA is an elliptic curve implementation of DSA. Functionally, where RSA and DSA require key lengths of 3072 bits to provide 128 bits of security, ECDSA can accomplish the same with only 256-bit keys. However, ECDSA relies on the same level of randomness as DSA, so the only gain is speed and length, not security.

**How do I view the SSL ciphers available for use on ESA?**

This document describes how to view the SSL ciphers that are available for use and supported on the Cisco Email Security Appliance (ESA). The SSL ciphers that are available for use and supported can be seen at any time by running the following from the CLI: sslconfig > verify

**What is AES 128 CBC?**

Advanced Encryption Standard with 128bit key in Cipher Block Chaining mode (AES 128 CBC) In 2013, researchers demonstrated a timing attack against several TLS implementations using the CBC encryption algorithm (see isg.rhul.ac.uk ). Additionally, the CBC mode is vulnerable to plain-text attacks in TLS 1.0, SSL 3.0 and lower.

### What cipher suite do I need for HTTP/2?

Implementing the cipher suite blacklist is optional, but Chrome and Firefox both do so. If you enable HTTP/2, you’ll absolutely need acceptable cipher suites (which include AES-GCM with DHE or ECDHE key exchange, but not HMAC, regardless of the key size).

**Which Siem components will be affected by the change to ciphers?**

Components that may be affected by this change include: SIEM Agent – Customers can use any supported cipher suite as described above. Microsoft Cloud App Security API – Custom applications and code that are utilizing the Microsoft Cloud App Security API must utilize supported suites to continue functioning.