AWS Access Key ID Regex for PHP

What this pattern does

This page provides a well-structured, multi-part regular expression for matching aws access key id, ported and verified for PHP. In security-sensitive code, using an unverified regex can open the door to both false positives and denial-of-service attacks. The snippet below is ready to drop into your PHP project — whether you're validating in a Laravel validator, a WordPress plugin, or a standalone PHP script.

Php Implementation

<?php
// AWS Access Key ID
// ReDoS-safe | RegexVault — Security > API Keys & Tokens

define('AWS_ACCESS_KEY_ID_PATTERN', '/^(AKIA|ASIA|AROA|AIDA|ANPA|ANVA|APKA)[A-Z0-9]{16,20}$/');

function validate_aws_access_key_id(string $input): bool {
    return (bool) preg_match(AWS_ACCESS_KEY_ID_PATTERN, $input);
}

// Example
var_dump(validate_aws_access_key_id("AKIAIOSFODNN7EXAMPLE")); // bool(true)

Test Cases

When to use this pattern

This pattern is drawn from the Security > API Keys & Tokens category and carries a ReDoS-safe certification. That matters for PHP developers because especially relevant in PHP where PCRE backtracking limits can trigger silent failures on malicious input. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

AWS key type prefixes: AKIA=long-term IAM user key, ASIA=temporary STS session key (expires), AROA=role, AIDA=IAM user, ANPA=managed policy, ANVA=version, APKA=public key. Always pair with Secret Access Key for signing — access key ID alone is not sufficient to authenticate.