Encryption Option Summary for Law Firms
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| Approach | Examples | Advantages | Disadvantages | Comments |
| Use encryption features built into products intended primarily for other uses. | "Password" features built into MS Word, WordPerfect, PK Zip and any other programs. | 1. Excellent protection
against "data mining" attacks that rely on plaintext scanning.
Good protection against unsophisticated snoops.
2. Probably no need to purchase any other products. 3. Minimal training time. |
1. Can easily be defeated
with inexpensive, commercially available anti-encryption software.
2. "Key management" is inconvenient (must share password by a separate, secure channel) and introduces a security risk not present with other types of software. |
Could be appropriate for some
lawyers and some clients.
I analogize this to placing an envelope on a letter to be sent by postal mail. It won't stop determined, sophisticated snoops, but it will deter some types of attack. |
| Use web-based encryption services. | Hushmail UPS Online Courier |
1. Probably more secure than
the class of products mentioned in previous block.
2. Low learning curve. 3. "Return receipt" is possible. |
Probably less secure than some alternatives. | This method relies on the SSL
encryption built into web browsers that is already widely used to
protect credit cards in transit. (There are many examples of credit card
numbers being stolen over the Net after arriving at a merchant site, but
none, as far as I know, of credit card numbers stolen while in transit).
Hushmail, has gotten some good reviews, but I have no personal information as to quality. UPS Document Exchange has the advantage of being backed by a large, well-capitalized company. |
| Use symmetric-based encryption products. | PC Crypto Web Crypto |
Conventional encryption is simple in concept, if not necessarily in actual use. | 1. Probably less secure than
some alternatives.
2. Key management is inconvenient. |
Could be a satisfactory solution for some lawyers who don't need the very highest level of security and are willing to put up with key management inconvenience. |
| Use S/MIME-based encryption products. | MS Outlook MS Outlook Express Netscape e-mail client Many others |
1. Simplified key management.
2. Very widely available, as they are included with |
1. Probably less secure than
some alternatives.
2. Each user needs to pay for a digital certificate (public-private key
pair, with the issuer digitally signing the public key). |
Probably a good choice for many lawyers. |
| Use other commercial public key-based encryption products. | Zixmail |
Simplified key management. | Probably less secure than some alternatives. | Probably a good choice for
many lawyers.
Zixmail advertises heavily, but I have no personal knowledge as to quality. |
| Use Pretty Good Privacy (PGP) | PGP | 1. Far better tested than any
other readily available product
2. Rates highly on "ease of use" in the sense that it is already so well respected and so widely in use that it is considered the de facto standard among a high percentage of those who are serious about security. |
Some learning curve, though not nearly as bad as often cracked up to be. | Probably the best choice for
a high level of security. Some prospective users fall into the trap of assuming that the safest security must also be the hardest to understand. This is a false assumption. Good crypto doesn't have to be harder to use than weak crypto. |
While PGP does have some clear advantages in many situations, it is far from being the be-all and end-all for e-mail security. Some law firms may prefer other options, and this chart is available to give an idea of the choices available, and an overview of their strengths and weaknesses.
In general, the lower down the chart, the more secure the method of communication. This is not intended to be precise, however. For example, no inference is intended that symmetric key encryption is necessarily more secure than public key encryption, except to the extent that easier key management (i.e., not having to exchange keys over the telephone, etc.) reduces risk.
This chart does not list one security problem shared by all e-mails: "traffic analysis." E-mail cannot work if the routing information in the header is encrypted. Therefore, snoops can determine who sent a message, when it was sent, and to whom it was sent, and (to the best of my knowledge) no encryption software available can prevent this.
This is the first iteration of this chart. I welcome comments and suggestions (particularly of other products to add, and their strengths and weaknesses). Send material to the Webmaster.
See related chart Approaches To E-mail Security.
Jerry Lawson
This page last revised: January 01, 2002.
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