Knowledge Base

ECDHE (Elliptic-curve Diffie-Hellman Ephemeral)

Ephemeral Elliptic-curve Diffie–Hellman^[432][433] is a variant of Elliptic-curve Diffie–Hellman^[114][115] key exchange that has forward secrecy^{[127][128][129][130]}, and does protect past sessions against future compromises. If long-term secret keys or passwords are compromised, encrypted communications and sessions recorded in the past cannot be retrieved and decrypted.

Always prefer cipher suites with PFS property over the non-PFS ones. Note that performance considerations implies preferring Ephemeral Elliptic-curve Diffie–Hellman^[432][433] over Ephemeral Diffie-Hellman^{[405][406][407][408]}.

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]}.