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TLS-DH-DSS-WITH-AES-128-GCM-SHA256 Cipher Suite
A breakdown of the Cipher Suite TLS_DH_DSS_WITH_AES_128_GCM_SHA256, its strengths, and its weaknesses.
Key Exchange Mechanism
Diffie Hellman - DH
Grade - B
Static Diffie Hellman (DH) does not use emphemeral (temporary) keys, meaning it violates perfect forward secrecy. Ephemeral Diffie Hellman (EDH) should be used instead.
Authentication
Digital Signature Standard - DSS
Grade - C
Low usage
Cipher
Advanced Encryption Standard - AES
Grade - A
AES should be used in cipher suites because it offers strong security with efficient performance, large block size (128 bits), and resistance to known attacks. Its widespread adoption and thorough analysis by the cryptographic community ensure reliability and robustness for encrypting sensitive data.
Hash
Secure Hash Algorithm 256 Bit - SHA256
Grade - A
Improving greatly from SHA1, SHA-256 and above create secure hashes through robust cryptographic algorithms that ensure collision resistance and preimage resistance. They process input data in fixed-size blocks, applying complex mathematical transformations that make it computationally impractical to reverse-engineer the original data from its hash.
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.
Cipher Mode
Galois/Counter Mode - GCM
Grade - A
GCM (Galois Counter Mode) is a mode of operation for block ciphers, offering both encryption and authentication. Widely used in cipher suites, GCM ensures data confidentiality and integrity with high efficiency and performance. It combines the Counter (CTR) mode for encryption with a Galois field-based authentication tag for data integrity. GCM’s parallelizable nature makes it particularly fast and suitable for high-speed networks and secure communications. By incorporating GCM, cipher suites provide robust security against unauthorized access and tampering, making it a preferred choice for modern cryptographic protocols.
