TLS-DHE-PSK-WITH-RC4-128-SHA Cipher Suite

Key Exchange Mechanism

Diffie Hellman Ephemeral - DHE

Grade - B

Diffie-Hellman Ephemeral (DHE) in cipher suites refers to a key exchange method where each session generates temporary, one-time-use (ephemeral) keys. This ensures forward secrecy, meaning if one session’s key is compromised, past and future sessions remain secure. DHE provides an added layer of protection against decryption by ensuring keys are used briefly and then discarded, enhancing security in TLS communications.

Authentication

Pre-Shared Key - PSK

Grade - A

PSK (Pre-Shared Key) cipher suites are used for authentication in secure communication protocols like TLS. They allow parties to establish a shared secret beforehand, ensuring confidentiality and integrity of data exchanges without the overhead of public key infrastructure (PKI), suitable for constrained environments or specific security requirements.

Cipher

Rivest Cipher 4 - RC4

Grade - D

RC4 should not be used as a cipher due to several vulnerabilities, including biases in its keystream and susceptibility to various attacks such as the Fluhrer-Mantin-Shamir attack. These weaknesses compromise the confidentiality and integrity of encrypted data, making RC4 unsuitable for secure communications in modern cryptographic applications. Deprecated in RFC 7465.

Hash

Secure Hash Algorithm - SHA

Grade - D

Chosen prefix attacks for SHA1 are feasible at an accessible cost to a well-funded adversary. This level of expense, while significant, does not pose a substantial barrier to attackers with sufficient resources, making such attacks a credible threat.

Key Size

128 Bit - 128

Grade - A

128-bit symmetric encryption keys are considered secure because they provide an astronomically large number of possible combinations (2^128), making brute-force attacks computationally infeasible with current technology. This level of security is sufficient for most practical purposes and is widely adopted in various encryption protocols.