· 2 min read
TLS-ECDH-RSA-WITH-RC4-128-SHA Cipher Suite
A breakdown of the Cipher Suite TLS_ECDH_RSA_WITH_RC4_128_SHA, its strengths, and its weaknesses.
Key Exchange Mechanism
Elliptic Curve Diffie Hellman - ECDH
Grade - B
Static Elliptic Curve Diffie Hellman (ECDH) does not use ephemeral (temporary) keys, meaning it violates perfect forward secrecy. ECDHE should be used in preference.
Authentication
Rivest, Shamir, Adleman - RSA
Grade - A
RSA as an authentication mechanism in cipher suites is secure because it relies on the difficulty of factoring large prime numbers. This makes it computationally infeasible for attackers to derive the private key from the public key, ensuring confidentiality and integrity in secure communications.
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.
