on the Requirements to the Algorithms of Advanced Electronic Signature

Adopted pursuant to CMD No. 17 dated 31 January 2002
(Promulgated, SG No. 15 dated 8 February 2002)

Chapter One

Article 1. (1) This Ordinance shall determine the requirements to the algorithms for advanced electronic signature.

(2) These requirements shall apply to the algorithms through which the data for advanced electronic-signature creation are generated (the cryptographic key pairs), and to the algorithms through which the very signature is created (the hashed messages, the combinations of private key and hashed message, and pseudo-random digital series). Such algorithms should be recognized in the practice as secure ones, and shall be adopted in documents in force (standards, technical specifications, recommendations, guides and reports).

(3) The Communications Regulation Commission shall publish and maintain a list of documents in force containing the technical requirements to the algorithms.

Article 2. (1) Any person generating data for advanced electronic-signature-creation, and any person verifying an advanced electronic signature, is obliged to follow and observe the requirements hereof in the process of such generation and verification.

(2) In case a person as per paragraph 1 is a certification-service-provider, he is obliged not to store or copy data for creation of private keys.

(3) The algorithms for verification of signatures represent a logical whole with the algorithms for electronic-signature-creation, and should be stored together.

Article 3. The owner of advanced electronic signature is liable to third conscientious parties in case he has used an algorithms not corresponding to the requirements herein while creating the private-and-public key pair.

Article 4. Any certification-service-provider, offering also a service for generation of data for advanced electronic-signature-creation, must incorporate a list of algorithms used by him to that end in the “Certificate Practice Statement” drawn pursuant to the requirements of the Ordinance on the Activities of Certification-Service-Providers, the Procedure for Termination Thereof, And the Requirements for Provision of Certification Services.

Chapter Two

Article 5. The purpose of the laid down requirements to algorithms for advanced electronic signature is the achievement of compliance with the functional securing requirements of the protection profile (PP) of the secure-electronic-signature-creation-device according to the common criteria (CC) for security evaluation as determined in documents in force.

Article 6. (1) The level of security as ensured by the algorithms and determined by the working factor for their compromising through the usage of contemporary, most powerful information-computing systems, has to be high enough.

(2) The realizations of the algorithms must be of module type, in order to ensure easy incorporation of new algorithms of higher level of security, if necessary.

Article 7. In order a high level of security to be achieved during the advanced electronic signature creation, a hardware device (a module based on chip-card with a micro-processor, own operation system, personal identificator (PIN) and/or biometric identification means) is to be used, which is capable of ensuring a higher level of security as compared to the software signature-creation-devices.

Article 8. (1) The secure signature creation device and the algorithms for generation of data for the signature creation are subject to verification.

(2) The verification as per paragraph 1 shall be carried out:

1. according to the requirements as laid down in documents in force of ETSI, CEN/ISSS regarding electronic signature;

2. by organizations accredited and approved for testing of cryptographic modules (Cryptographic Module Testing Laboratories - CMTL) for compliance with the common criteria (CC) of security, according to the documents recognized in the international practice.

(3) Any organization as per paragraph 2, point(2) above shall issue a test report of consumer cryptographic modules submitted for evaluation.

(4) A duly accredited certifying organization in the field of security shall issue to the owner of the assessed cryptographic module a certificate of validity on the basis of the test report.

Article 9. (1) The algorithms used for an advanced electronic signature should meet the requirements as laid down in Annex No. 1.

(2) The parameters of the data for advanced electronic signature creation should meet the requirements as laid down in Annex No. 2.

Article 10. The Communications Regulation Commission shall publish and maintain also lists of:

1. organizations carrying out verification of security of cryptographic modules, according to Article  8(2), point 2;

2. documents as per Articles 5 and 8(2), points 1 and 2, and as per Annexes No. No. 1 and 2 to Article  9.


Single Paragraph. This Ordinance is adopted pursuant to Article  16(3) in relation to Article  30(1) of the Law on Electronic Document and Electronic Signature.


Annex No. 1 to Article  9(1)

Specific Requirements to the Algorithms Used for Advanced Electronic Signatures

1. Hash-functions:

1.1. The following functions recognized in the international practice as secure ones and determined as such in current hash-function documents may be used with the algorithms for creation of advanced electronic signature:

А. SHA-1 (Secure Hash Algorithm);

B. RIPEMD-160 (Race Integrity Primitives Evaluation Message Digest).

1.2. Other hash-functions capable of ensuring at least the same level of security, and which are recognized in documents in force, may as well be used.

1.3. Pseudo-casual digits may as well be used to supplement the hash-data. It is necessary that only generators of casual digits, as recognized in documents in force, are used.

2. Algorithms for advanced electronic signature:

2.1. Where advanced electronic signature is created, any one of the following algorithms, which are recognized in the practice as secure ones (with a short addendum on the basis of hash-functions), recognized in documents in force, should be used:

А. RSA (Rivest-Shamir-Adelman);

B. DSA (Digital Signature Algorithm);

C. ECDSA ( Elliptic Curve Digital Signature Algorithm).

2.2. The creation of key pairs should be made through algorithms corresponding to the specifications of algorithms as pointed out in point 2.1.

2.3. Other algorithms may as well be used for creation of key pairs and electronic signatures, which are capable of ensuring at least the same level of security as of those pointed out in point 2.1. and which are recognized in documents in force.

3. Abstract languages and encoding formats: It is recommended that the abstract languages and encoding formats used for advanced electronic signatures, including for XML-documents (documents in the eXtensible Markup Language format), and the advance electronic signatures used in XML-documents, correspond to the requirements of specifications, which practical application is internationally recognized.


Annex No. 2 to Article  9 (2)

Specific Requirements to the Parameters of Data Used for Creation of Advanced Electronic Signature

1. The lengths of hash-functions should be no less than 128 bits in order to be computably secure.

2. The lengths of keys of data for creation of advanced electronic signature should be of at least 1024 bits for the RSA and DSA algorithms, and of at least 160 bits for the ECDSA algorithms.

3. The length of the private key of any certification-service-provider should be equal to or greater than the length of the private key used for advanced electronic signature creation.

4. Any tolerance in the conditions as per points 1 and 2 is permissible in compliance with the changes in the used algorithms as published in the periodic information document of the European Union: “Algorithms and Parameters for Electronic Signatures of High Security”, prepared by the group for research of algorithms (ALGO) to the European Electronic Signature Standardization Initiative (EESSI).