Knowledge Base

ECDH (Fixed Elliptic-curve Diffie-Hellman)

Static Elliptic-curve Diffie–Hellman^[434][435] key exchange is a variant of the Elliptic-curve Diffie–Hellman^[114][115] key exchange protocol using elliptic-curve cryptography^{[118][119][120][121]}. It has no forward secrecy^{[127][128][129][130]}, and does not protect past sessions against future compromises. If long-term secret keys or passwords are compromised, encrypted communications and sessions recorded in the past can be retrieved and decrypted. Leading client applications do not use this algorithm. Unless your application or requirements specifically call for their use, it is generally safer to avoid cipher suites that are not adopted and supported by a critical mass of the industry.

Remove the cipher suite from the list of cipher suites supported by your server or replace the cipher suite with it's Ephemeral Diffie-Hellman^{[405][406][407][408]} version.

RSA

Rivest–Shamir–Adleman^{[275][276][277]} is a digital signature^{[107][108][109][110]} algorithm, which is considered secure, however there are known weaknesses^{[278][279][280][281][282]}.

NULL

Encryption algorithm is a null encryption^[360][361] that cannot provide confidentiality^[91][92][93], so connection is available or disclosed to unauthorized individuals, entities, or processes.

Remove the cipher suite from the list of cipher suites supported by your server.

SHA-1

message authentication code^{[135][136][137][138]} is a hashed message authentication code^{[139][140][141][142][143][144][145]} which is considered secure^[462], despite the fact that the underlayingcryptographic hash function^{[94][95][96][97]} (Secure Hash Algorithm 1^{[202][203][204]}) is considered insecure^{[205][206][207][208][209][210][211]}.

If your application or requirements specifically call for the use of a message authentication code^{[135][136][137][138]} that does not provide authenticated encryption^[74] prefer block cipher mode of operation^{[82][83][84][85][86]} (eg: counter with CBC-MAC^[32][33][34], Galois/Counter Mode^{[46][47][48][49]} or message authentication code^{[135][136][137][138]} (eg: Poly1305^[458][459]) that proved authenticated encryption over the ones which does not provide it. In case of a hashed message authentication code^{[139][140][141][142][143][144][145]} prefer message authentication code^{[135][136][137][138]} based on Secure Hash Algorithm 2^{[212][213][214]} over the ones based on Secure Hash Algorithm 1^{[202][203][204]}.