Machine Key Generator

Algorithm preset

SHA1 + AES — validation=SHA1, decryption=AES (recommended)

validationKey 64 bytes · decryptionKey 32 bytes

SHA1 + 3DES — validation=SHA1, decryption=3DES (classic)

validationKey 64 bytes · decryptionKey 24 bytes

HMACSHA256 + AES — validation=HMACSHA256, decryption=AES (modern)

validationKey 64 bytes · decryptionKey 32 bytes

Keys are generated using crypto.getRandomValues() — the same cryptographic RNG used by your OS. Place the generated snippet inside the <system.web> section of your web.config. Use the same keys on all nodes in a web farm so session state and forms authentication tokens remain valid across servers.

ASP.NET Machine Key Generator