STARTTLS

E6787
email security mechanism protocol command

STARTTLS is a protocol command used to upgrade an existing unencrypted connection to a secure TLS-encrypted one, commonly in email and other text-based communication protocols.

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Observed surface forms (4)

Surface form Occurrences
LDAP over TLS 1
SMTP over TLS 1
SMTP service extension keyword STARTTLS 1

Statements (48)

Predicate Object
instanceOf email security mechanism ⓘ
protocol command ⓘ
alternativeTo using a separate port for implicit TLS ⓘ
category email security ⓘ
transport layer security ⓘ
commandType extension command ⓘ
definedFor SMTP ⓘ
definedIn RFC 3207 ⓘ
effect switches communication from plaintext to encrypted within same TCP session ⓘ
enables confidentiality ⓘ
integrity ⓘ
opportunistic encryption ⓘ
server authentication ⓘ
follows initial plaintext protocol negotiation ⓘ
fullName Start Transport Layer Security ⓘ
imapCommandKeyword STARTTLS ⓘ
introducedInYear 2002 ⓘ
layer application layer ⓘ
operatesOn existing plaintext connection ⓘ
pop3CommandKeyword STLS ⓘ
precedes TLS handshake ⓘ
purpose upgrade an existing plaintext connection to a TLS-encrypted connection ⓘ
relatedConcept SMTPS ⓘ
implicit TLS ⓘ
opportunistic TLS ⓘ
requires TLS handshake after command acceptance ⓘ
support from both client and server ⓘ
securityProperty does not guarantee encryption if peers do not support TLS ⓘ
vulnerable to downgrade attacks if not enforced ⓘ
smtpCommandKeyword STARTTLS ⓘ
standardizedBy Internet Engineering Task Force ⓘ
surface form: IETF
status widely deployed in email infrastructure ⓘ
usedInProtocol ACAP ⓘ
FTP ⓘ
IMAP ⓘ
IRC ⓘ
LDAP ⓘ
NNTP ⓘ
POP3 ⓘ
SMTP ⓘ
XMPP ⓘ
usedOnPort 110 ⓘ
143 ⓘ
25 ⓘ
5222 ⓘ
587 ⓘ
usesProtocol SSL ⓘ
TLS ⓘ

Referenced by (7)

Full triples — surface form annotated when it differs from this entity's canonical label.

TLS 1.0 → commonlyUsedWith → STARTTLS ⓘ
this entity surface form: SMTP over TLS
RFC 3207 → defines → STARTTLS ⓘ
this entity surface form: SMTP service extension keyword STARTTLS
SMTP AUTH → relatedTo → STARTTLS ⓘ
RFC 3207 → specifies → STARTTLS ⓘ
this entity surface form: STARTTLS extension for SMTP
TLS → usedByProtocol → STARTTLS ⓘ
subject surface form: X.509 certificate
this entity surface form: LDAP over TLS