48 CFR 504.502: 504.502 Policy.

Use of electronic signatures is encouraged and can be used to sign and route documents in GSA's IT systems to contractually obligate funds. The method of authentication used for electronic signatures shall be consistent with the level (1-4) determined from the e-authentication risk assessment in accordance with OMB M-04-04, E-authentication Guidance for Federal Agencies, and the respective technology safeguards applicable to that level or risk from National Institute of Standards and Technology 800-63, Electronic Authentication Guideline.