ISM control lookup / Topic

Guidelines for cryptography

71 controls · September 2026 edition

• ISM-0142 · Reporting cryptographic-related cyber security incidents

  The compromise or suspected compromise of cryptographic equipment or associated keying material is reported to the chief information security officer, or one of their delegates, as soon as possible after it occurs.

• ISM-0455 · Data recovery

  Where practical, cryptographic equipment, applications and libraries provide a means of data recovery to allow for circumstances where the encryption key is unavailable due to loss, damage or failure.

• ISM-0457 · Cryptographic implementation assurance

  Cryptographic equipment, applications or libraries that have completed a Common Criteria evaluation against an ASD-endorsed Protection Profile are used when encrypting media that contains OFFICIAL: Sensitive or PROTECTED data.

• ISM-0460 · Cryptographic implementation assurance

  HACE is used when encrypting media that contains SECRET or TOP SECRET data.

• ISM-0462 · Handling encrypted IT equipment and media

  When a user authenticates to the encryption functionality of IT equipment or media, it is treated in accordance with its original sensitivity or classification until the user deauthenticates from the encryption functionality.

• ISM-0465 · Cryptographic implementation assurance

  Cryptographic equipment, applications or libraries that have completed a Common Criteria evaluation against an ASD-endorsed Protection Profile are used to protect OFFICIAL: Sensitive or PROTECTED data when communicated over insufficiently secure networks, outside of appropriately secure areas or via public network infrastructure.

• ISM-0467 · Cryptographic implementation assurance

  HACE is used to protect SECRET and TOP SECRET data when communicated over insufficiently secure networks, outside of appropriately secure areas or via public network infrastructure.

• ISM-0469 · Using cryptographic protocols

  An AACP or high assurance cryptographic protocol is used when encrypting data in transit.

• ISM-0471 · Using cryptographic algorithms

  Only AACAs or high assurance cryptographic algorithms are used by cryptographic equipment, applications and libraries.

• ISM-0472 · Using Diffie-Hellman

  When using DH for agreeing on encryption session keys, a modulus of at least 2048 bits is used, preferably 3072 bits.

• ISM-0474 · Using Elliptic Curve Diffie-Hellman

  When using ECDH for agreeing on encryption session keys, a base point order and key size of at least 224 bits is used, preferably the NIST P-384 curve.

• ISM-0475 · Using the Elliptic Curve Digital Signature Algorithm

  When using ECDSA for digital signatures, a base point order and key size of at least 224 bits is used, preferably the P-384 curve.

• ISM-0476 · Using Rivest-Shamir-Adleman

  When using RSA for digital signatures, and transporting encryption session keys (and similar keys), a modulus of at least 2048 bits is used, preferably 3072 bits.

• ISM-0477 · Using Rivest-Shamir-Adleman

  When using RSA for digital signatures, and for transporting encryption session keys (and similar keys), a different key pair is used for digital signatures and transporting encryption session keys.

• ISM-0479 · Using symmetric cryptographic algorithms

  Symmetric cryptographic algorithms are not used in Electronic Codebook Mode.

• ISM-0481 · Using cryptographic protocols

  Only AACPs or high assurance cryptographic protocols are used by cryptographic equipment, applications and libraries.

• ISM-0484 · Configuring Secure Shell

  The SSH daemon is configured to:

• ISM-0485 · Authentication mechanisms

  Public key-based authentication is used for SSH connections.

• ISM-0487 · Automated remote access

  When using logins without a password for SSH connections, the following are disabled:

• ISM-0488 · Automated remote access

  If using remote access without the use of a password for SSH connections, the ‘forced command’ option is used to specify what command is executed and parameter checking is enabled.

• ISM-0489 · SSH-agent

  When SSH-agent or similar key caching applications are used, cached private keys have a maximum lifetime of four hours and, where applicable, screen locks are used on workstations and servers.

• ISM-0490 · Configuring Secure/Multipurpose Internet Mail Extensions

  Versions of S/MIME earlier than S/MIME version 3.0 are not used for S/MIME connections.

• ISM-0494 · Mode of operation

  Tunnel mode is used for IPsec connections; however, if using transport mode, an IP tunnel is used.

• ISM-0496 · Protocol selection

  The ESP protocol is used for authentication and encryption of IPsec connections.

• ISM-0498 · Security association lifetimes

  A security association lifetime of less than four hours (14400 seconds) is used for IPsec connections.

• ISM-0499 · Communications security doctrine

  Communications security doctrine and policy produced by ASD for the management and operation of HACE is complied with.

• ISM-0501 · Transporting cryptographic equipment

  Keyed cryptographic equipment is transported based on the sensitivity or classification of its keying material.

• ISM-0507 · Cryptographic key management processes and procedures

  Cryptographic key management processes, and supporting cryptographic key management procedures, are developed, implemented and maintained.

• ISM-0994 · Asymmetric cryptographic algorithms

  ECDH is used in preference to DH.

• ISM-0998 · Integrity algorithms

  AUTH_HMAC_SHA2_256_128, AUTH_HMAC_SHA2_384_192, AUTH_HMAC_SHA2_512_256 or NONE (only with AES-GCM) is used for authenticating IPsec connections, preferably NONE.

• ISM-0999 · Diffie-Hellman groups

  DH or ECDH is used for key establishment of IPsec connections, preferably 384-bit random ECP group, 3072-bit MODP Group or 4096-bit MODP Group.

• ISM-1000 · Perfect Forward Secrecy

  PFS is used for IPsec connections.

• ISM-1080 · Using cryptographic algorithms

  An AACA or high assurance cryptographic algorithm is used when encrypting data at rest.

• ISM-1091 · Reporting cryptographic-related cyber security incidents

  Keying material is changed when compromised or suspected of being compromised.

• ISM-1139 · Configuring Transport Layer Security

  Only the latest version of TLS is used for TLS connections.

• ISM-1233 · Key exchange

  IKE version 2 is used for key exchange when establishing IPsec connections.

• ISM-1369 · Configuring Transport Layer Security

  AES-GCM is used for encryption of TLS connections.

• ISM-1370 · Configuring Transport Layer Security

  Only server-initiated secure renegotiation is used for TLS connections.

• ISM-1372 · Configuring Transport Layer Security

  The ephemeral variant of DH or ECDH is used for key establishment of TLS connections.

• ISM-1373 · Configuring Transport Layer Security

  Anonymous DH is not used for TLS connections.

• ISM-1374 · Configuring Transport Layer Security

  SHA-2-based certificates are used for TLS connections.

• ISM-1375 · Configuring Transport Layer Security

  SHA-2 is used for the Hash-based Message Authentication Code (HMAC) and pseudorandom function (PRF) for TLS connections.

• ISM-1446 · Using Elliptic Curve Cryptography

  When using elliptic curve cryptography, a suitable curve from NIST SP 800-186 is used.

• ISM-1449 · Authentication mechanisms

  SSH private keys are protected with a password or a key encryption key.

• ISM-1453 · Configuring Transport Layer Security

  Perfect Forward Secrecy (PFS) is used for TLS connections.

• ISM-1506 · Configuring Secure Shell

  The use of SSH version 1 is disabled for SSH connections.

• ISM-1553 · Configuring Transport Layer Security

  TLS compression is disabled for TLS connections.

• ISM-1629 · Using Diffie-Hellman

  When using DH for agreeing on encryption session keys, a modulus and associated parameters are selected according to NIST SP 800-56A Rev. 3.

• ISM-1759 · Using Diffie-Hellman

  When using DH for agreeing on encryption session keys, a modulus of at least 3072 bits is used, preferably 3072 bits.

• ISM-1761 · Using Elliptic Curve Diffie-Hellman

  When using ECDH for agreeing on encryption session keys, NIST P-256, P-384 or P-521 curves are used, preferably the NIST P-384 curve.

• ISM-1762 · Using Elliptic Curve Diffie-Hellman

  When using ECDH for agreeing on encryption session keys, NIST P-384 or P-521 curves are used, preferably the NIST P-384 curve.

• ISM-1763 · Using the Elliptic Curve Digital Signature Algorithm

  When using ECDSA for digital signatures, NIST P-256, P-384 or P-521 curves are used, preferably the NIST P-384 curve.

• ISM-1764 · Using the Elliptic Curve Digital Signature Algorithm

  When using ECDSA for digital signatures, NIST P-384 or P-521 curves are used, preferably the NIST P-384 curve.

• ISM-1765 · Using Rivest-Shamir-Adleman

  When using RSA for digital signatures, and transporting encryption session keys (and similar keys), a modulus of at least 3072 bits is used, preferably 3072 bits.

• ISM-1766 · Using Secure Hashing Algorithms

  When using SHA-2 for hashing, an output size of at least 224 bits is used, preferably SHA-384 or SHA-512.

• ISM-1767 · Using Secure Hashing Algorithms

  When using SHA-2 for hashing, an output size of at least 256 bits is used, preferably SHA-384 or SHA-512.

• ISM-1768 · Using Secure Hashing Algorithms

  When using SHA-2 for hashing, an output size of at least 384 bits is used, preferably SHA-384 or SHA-512.

• ISM-1769 · Using symmetric cryptographic algorithms

  When using AES for encryption, AES-128, AES-192 or AES-256 is used, preferably AES-256.

• ISM-1770 · Using symmetric cryptographic algorithms

  When using AES for encryption, AES-192 or AES-256 is used, preferably AES-256.

• ISM-1771 · Encryption algorithms

  AES is used for encrypting IPsec connections, preferably ENCR_AES_GCM_16.

• ISM-1772 · Pseudorandom function

  PRF_HMAC_SHA2_256, PRF_HMAC_SHA2_384 or PRF_HMAC_SHA2_512 is used for IPsec connections, preferably PRF_HMAC_SHA2_512.

• ISM-1802 · High Assurance Cryptographic Equipment

  HACE are issued an Approval for Use by ASD and operated in accordance with the latest version of their associated Australian Communications Security Instructions.

• ISM-1917 · Transitioning to post-quantum cryptography

  The development and procurement of new cryptographic equipment, applications and libraries ensures support for the use of ML-DSA-87, ML-KEM-1024, SHA-384, SHA-512 and AES-256 by no later than 2030.

• ISM-1990 · Using post-quantum cryptographic algorithms

  When using ML-DSA and ML-KEM, as per FIPS 204 and FIPS 203 respectively, adherence to pre-requisite FIPS 140-3 validation is preferred.

• ISM-1991 · Using the Module-Lattice-Based Digital Signature Algorithm

  When using ML-DSA for digital signatures, ML-DSA-65 or ML-DSA-87 is used, preferably ML-DSA-87.

• ISM-1992 · Using the Module-Lattice-Based Digital Signature Algorithm

  When using ML-DSA for digital signatures, the hedged variant is used whenever possible.

• ISM-1993 · Using the Module-Lattice-Based Digital Signature Algorithm

  Pre-hashed variants of ML-DSA-65 and ML-DSA-87 are only used when the performance of default variants is unacceptable.

• ISM-1994 · Using the Module-Lattice-Based Digital Signature Algorithm

  When the pre-hashed variants of ML-DSA-65 and ML-DSA-87 are used, at least SHA-384 and SHA-512 respectively are used for pre-hashing.

• ISM-1995 · Using the Module-Lattice-Based Key Encapsulation Mechanism

  When using ML-KEM for encapsulating encryption session keys (and similar keys), ML-KEM-768 or ML-KEM-1024 is used, preferably ML-KEM-1024.

• ISM-1996 · Post-quantum traditional hybrid schemes

  When a post-quantum traditional hybrid scheme is used, either the post-quantum cryptographic algorithm, the traditional cryptographic algorithm or both are AACAs.

• ISM-2073 · Transitioning to post-quantum cryptography

  A post-quantum cryptography transition plan is developed, implemented and maintained.