Electronic signatures on aircraft maintenance records: what FAA and EASA accept

Both the FAA and EASA accept electronic maintenance records and electronic signatures, including on release certificates. Neither tells you which cryptography to use. They set out what a signature must achieve, and leave the algorithm to you. That choice matters more than it looks for records that must be trusted for decades.

FAA: AC 120-78B

The FAA's guidance is Advisory Circular 120-78B, issued on 11 December 2024. It replaced AC 120-78A, which many articles still cite.¹ It is guidance rather than regulation: an acceptable means of compliance, not the only one. It applies to Flight Standards entities, including Part 43 maintainers and Part 145 repair stations, but not to design and production approvals.

The AC defines an electronic signature as "functionally equivalent to a handwritten signature." The elements it lists are, in its own words, that the signature is:

• "unique to the signer" and "under the sole control of the signer";
• "executed or adopted by a person with the intent to sign" as "the result of a deliberate action";
• able to prevent the signer from denying it (nonrepudiation); and
• "permanent and the information to which it is attached is unalterable without a new signature." Once signed, a document "cannot be edited."

For records, the AC asks for "equivalent or better data integrity, accuracy, and accessibility" than paper, controlled access, records "preserved and unalterable without the appropriate certification, verification, and/or authentication," backups and regular audits. It sets no retention period of its own; that comes from the operating rules, for example at least two years for a repair station's records under 14 CFR 145.219.⁶

Electronic 8130-3

FAA Order 8130.21J (September 2025) states that Form 8130-3 "may be filled out and signed electronically," pointing to AC 120-78 for an acceptable means.³ For maintenance releases, AC 43-9D says repair stations and air carriers may use systems that generate an electronic version of the form, with the signature applied electronically and data "held in a secure database." It adds: "The system should not overwrite or destroy the original record."²

EASA: electronic Form 1 and electronic records

EASA's acceptable means of compliance for the EASA Form 1 accept "an electronic EASA Form 1 or equivalent."⁴ The organisation's procedure goes to its competent authority, and the system should not allow a blank form to be signed and should "provide a high degree of assurance that the data has not been modified after signature." Block 14b then reads "Electronic Signature on File." Electronic exchange between trading partners is voluntary, and EASA points to an established industry method, ATA Spec 2000 Chapter 16, the industry standard for exchanging release certificates electronically.⁵

For records generally, the AMC to 145.A.55 and CAMO.A.220 accept paper, electronic or mixed records, organised for "traceability and retrievability throughout the required retention period," with a backup updated within 24 hours, kept in a different location, and safeguards against unauthorised alteration. The AMC to M.A.305 asks electronic systems to "ensure the authenticity of the record," with assurance that it has not been modified after creation, and to be "maintained against technological obsolescence."

Neither regulator names an algorithm

AC 120-78B notes that digital signatures are "based on Public Key Infrastructure (PKI) cryptography" and are typically the most secure form, but requires no algorithm or key length. EASA's AMC describes the signature as "an electronically generated value based on a cryptographic algorithm" without naming one. Neither text mentions post-quantum cryptography.

In practice, today's PKI signatures are RSA or elliptic-curve signatures. Those are the algorithms that standards bodies propose to retire over the next decade because a large enough quantum computer could forge them.

Where the requirements meet the timeline

Look at the requirements together: a signature must prevent repudiation, the record must stay unalterable for the whole retention period, and EASA asks for protection against technological obsolescence. For life-limited parts and status records that travel with an aircraft for decades (see how long records must be kept), the retention period is longer than the expected life of today's signature algorithms. A record signed with RSA or ECDSA today meets the rules today. Whether it still proves anything in 2045 depends on what happens to those algorithms, and on whether the record's integrity was anchored to something that will hold. That is the subject of post-quantum signatures for records that must last 30 years.