Glossary

E-signatures, defined.

Plain-English definitions of the terms that actually matter when you sign — the legal ones, the technical ones, and the ones vendors love to over-complicate.

Advanced Electronic Signature (AES)

An Advanced Electronic Signature (AES) is the middle eIDAS tier: it is uniquely linked to and identifies the signer and detects any change made to the document after signing.

Audit Trail

An audit trail is the time-stamped, tamper-evident record of every event in a signing process, showing who did what and when to prove a signature is genuine.

Certificate Authority (CA)

A Certificate Authority is a trusted organization that verifies identities and issues digital certificates, binding a person or entity to a public key.

Digital Signature

A digital signature is a cryptographic technique using public key infrastructure, certificates, and hashing to prove who signed a document and that it has not been altered. It is a type of electronic signature, not a synonym.

eIDAS

eIDAS is EU Regulation (EU) No 910/2014, which governs electronic signatures across the EU and defines three tiers: SES, AES, and QES.

Electronic Seal (e-Seal)

Under eIDAS, an electronic seal links a document to an organization rather than a person, evidencing that the document came from that legal entity and has not been altered.

Electronic Signature

An electronic signature is any electronic sound, symbol, or process attached to a record and adopted by a person with the intent to sign it.

ESIGN Act

The ESIGN Act is a US federal law from 2000 that gives electronic signatures and records the same legal effect as paper ones in interstate and foreign commerce.

Hash (Cryptographic Hash)

A cryptographic hash is a fixed-length fingerprint calculated from a document. Any change to the file, even one character, produces a completely different hash, which is how tampering is detected.

Non-Repudiation

Non-repudiation is the property that a signer cannot credibly deny having signed a document, because the record proves who signed, that nothing changed, and when.

Public Key Infrastructure (PKI)

Public Key Infrastructure (PKI) is the framework of key pairs, digital certificates, and certificate authorities that lets a digital signature be created and independently verified.

Qualified Electronic Signature (QES)

A Qualified Electronic Signature is the highest eIDAS tier: an advanced signature made with a qualified device and a qualified certificate, legally equal to a handwritten one across the EU.

Signature Field

A signature field is the marked spot on a document where a signer applies their signature. The term also covers fillable fields like date, initials, and text.

Signer Authentication

Signer authentication is how an e-signature platform confirms a signer is who they claim to be, using methods like email links, one-time codes, or ID checks.

Signing Certificate

A digital certificate that ties a signer's identity to a public key, letting software create and verify a tamper-evident digital signature.

Simple Electronic Signature (SES)

A Simple Electronic Signature (SES) is the baseline eIDAS tier, such as a typed name or clicked box. It cannot be denied legal effect or rejected as evidence solely for being electronic.

Tamper-Evident Seal

A cryptographic seal applied to a document after signing so any later change is detectable. It protects document integrity and helps prove nothing was altered.

Timestamp

A trusted record of the exact date and time an action like signing happened, captured in the audit trail so you can prove when a document was signed.

UETA

UETA (1999) is a model state law adopted by 49 states plus D.C. that gives electronic records and signatures the same legal effect as paper; New York uses its own ESRA instead.

Wet Signature

A wet signature is a traditional pen-on-paper signature made in physical ink. For most everyday documents, electronic signatures carry the same legal weight.

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