Encryption Regulation
Presentation 12 June 2001
Security and Encryption
David Swarbrick
With Central Law Training June 12, 2001
Summary
- Encryption Technologies
- Regulation of Investigatory Powers Act 2000
- Electronic Communications Act 2000
- Others – PACE/Terrorism Act 2000
Core Technology - Encryption
- Symmetric Key Encryption
- Asymmetric Key Encryption
- Combinations
- Underlies all e-commerce
- Part of delivery of software
- Identity
- Privacy
- Signing
- transactions
Symmetric Key Encryption
Also ‘single key’ or ‘private key’ encryption
Same key used both to encrypt (or scramble) the message, and to decrypt it.
Fast, Secure, easy to manage
Difficulty with keys
First communication must be secret to achieve secrecy.
Keeping the key secret.
Asymmetric Key Encryption
One key split in two
Private Key – is kept absolutely private
Public Key – can be distributed widely
Enables
Great flexibility
Secure communication without prior arrangement
Electronic commerce- digital signatures
Complex – must be understood
Asymmetric Use
Privacy - Encrypt with
Recipient’s public key
Decrypted by recipient with
His own private key
Only he can read it, (not even sender).
Authenticity - Encrypt
With Sender's private key
Decrypted by recipient with
Sender's Public key
Can only come from sender. Has not been changed.
Comparison
Symmetric
Attaches to the message
Can be
Simple
Speedy
Secure
Requires
Trust in recipient
Secure first channel
Asymmetric
Attaches to the person
Can be
Flexible
No prior trust in, contact with addressee
Complex
Requires
Trusted Third Party
Enables
E-commerce
Message Digest
Software creates a short series of characters – uniquely related to a document.
Post public key – possibly certified by TTP
Use
Generate MD for the document
Encrypt MD with own private key – (the signature)
Send document in plain with the encrypted MD
Recipient can reverse the process with public key to verify the signature.
Session Keys
Combines all three techniques
Generate Private key – one session /message only
Encrypt
the message with the session key
The session key with the recipient’s public key
Recipient
Use his Private key to decrypt the session key
Uses session key to decrypt the message
RIP said to give particular significance to this form of encryption.
Very widely used – but not RIP proof
Key Management
Encryption technology can be secure.
But managing keys almost impossible.
Key is equal in value to what it protects.
Combining keys – eggs and baskets
How can keys be looked after?
Third party systems – No - Can only rely upon own memory.
How many keys?
Do not underestimate this as a problem
Bio-Metrics
Use of physical attribute as key.
A very powerful solution. Appears to remove Key Management problems.
Considered for Passports, and e-conveyancing
Violates fundamental rule - the ‘key’ is not revocable if compromised.
All systems must translate the attribute into electronic form and therefore copyable form.
What happens if someone copies that feature? Eg image taken of retina for eye test. Lifetime exclusion?
Regulation of Investigatory Powers Act 2000
Four parts
Part I Regulates Interception of Communications
Part II Regulates Covert and Intrusive Surveillance
Part III Recovery of Encrypted Material
Provisions for Intelligence Services (not covered)
Extremely detailed and technical.
RIPA 2000 Part I – Chapter I Interception
Extends restrictions on interception of materials to
E-mails, and
Private networks
Material gathered under a warrant is not evidence s17
Difficulties for employers. Lawful Business Practice Regulations/Data Protection Guidelines (soon … real soon)
Facilities for ‘tapping’ in to e-mail networks s12.
Echelon system – outsourcing of interception?
RIPA 2000 Part 1 Chapter II and Part II – Surveillance
Part I Chapter II – Acquisition of Communications Data ss 21- 24
‘Traffic Data’ analysis of who is talking to whom – not what is being said
Authorised under warrant - admissible
Part II ‘covert’ and ‘intrusive’ surveillance
Previously unregulated
Whole new system of authorisations
RIPA 2000 Part III – Encryption
Much wider than ‘encryption’
Service of Notices requiring:
s49 Decryption (or 2 years) and/or
s51 Surrender of Key (s51), and/or
Secrecy Requirements (or 5 years)
Extreme Controversy
Impossible balance between law-enforcement and privacy and business needs
Takes no account of value of encryption in preventing crime.
RIPA 2000 Part III – Protections
Commercial concerns
s49(5) serve on senior employee
Keys
‘special situations’ and proportionate s50(4)
Signature Keys s49(9)
- Is intended to be used only as signature key and
- Has only been so used
- No real protection – by definition officer believes has been ‘so used’
Burden of proof s53(2)
RIPA 2000 Part III – Secrecy
s54 Tipping Off
Infects anyone who becomes aware of it
Inappropriately inherited from IOCA and other similar
Very different – ‘New Staasi’
Served on private individuals, not trained professional
Greater number – each recipient must be served
The innocent end of the communication
Affects privacy of other innocent parties
Undermines e-commerce
Whose keys and how many have been compromised?
‘Re-assurance’ revocation of compromised key is not tipping off.
Electronic Communications Act 2000 (ECA)
Part I – Regulation of Encryption Service Providers
Part II – Recognition of Digital etc Signatures
Part III – Modification of Telecommunications Licences (not covered)
Implements EU Digital Signatures Directive
ECA 2000 Part I
Regulation of Cryptography Service Providers
Certifying Authorities/Trusted Third Parties
Digital Certificates, or
Secure/Private Storage
Voluntary register
But may become involuntary.
No requirement for Key escrow s14
Part II
Facilitation of Electronic Commerce etc
S 7 Admissibility of
Digital Signatures, and
Certificates supporting signatures
Peculiar definition – s7(2)
cf RIP
Modification of Legislation
To ‘authorise or facilitate use of electronic communications/storage’ Piecemeal approach (cf Australia)
Companies Act, Local Government, Land Registry
Export Controls
Wassenaar Agreement – Encryption is classified as Dual Use Weapon
Export Control Regimes
Unpredictable consequences
Relaxed, but not completely
Effects
Has been used to restrict and discourage use of encryption
US challenges to export of PGP
Resources
www.swarb.co.uk - Posted copy of this and similar presentations.
www.jsboard.co.uk – Judicial StudiesBoard
www.scl.org - Society for Computers and Law – Join - (Particularly C&L Jan 2000)
The Code Book – Singh - excellent
www.cryptome.org – International policy developments
www.fipr.org - Foundation for Information Policy
http://elj.warwick.ac.uk/jilt - Journal of Information Law and Technology
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